An Honest Review of Fitbit for Menstrual Cycle Tracking

You may know that the Fitbit app has some built in menstrual cycle tracking features, but many people do not know that it has other features that may be useful for menstrual cycle tracking. In this article, I will review the pros and cons of the Fitbit app as it relates to cycle tracking for people who ovulate. For context, I use a Fitbit Charge III.

The most basic feature that Fitbit offers for cycle tracking is recording bleeding dates of menstruation and then displaying a predicted fertile window based on average cycle length.

The pink bar represents the length of menstruation. The blue bar represents a predicted fertile window. The flower symbol represents predicted ovulation.

The user needs to remember to input menstuation each cycle. Once it is inputted, Fitbit will generate the blue fertile window. This fertile window should NOT be used for avoiding pregnancy, as it is only based on cycle length and not real-time fertility signs like cervical mucus or basal body temperature.

Once menstruation is entered, it will also begin a countdown until your next predicted menstrual cycle.

Countdown until menstruation in the app.

Unfortunately, I do not find this basic feature very useful for anyone who has any cycle variation. Even though my cycle length has increased over the last year, Fitbit has not automatically updated my cycle lengths. The app does not appear to be very adaptive without user input.

In addition to tracking bleeding the app offers options for:

  • Mood
  • Plan B (morning after)
  • Ovulation tests (better called luteinizing hormone tests)
  • Cervical mucus (Taking Charge of Your Fertility categories)
  • Cyclical symptoms like acne

It is rather disappointing that the app does not include options to mark pregnancy when it occurs, especially since we know that this changes daily calories burned and heart rate, to name just two effected areas of the app.

A really cool feature that I do like is the ability to show cycle trends like flow intensity and cramps. The same screen that displays this will also let you scroll through all past cycle lengths.

In the settings of this screen, you can also decide to toggle off predictions. For people avoiding pregnancy, I do recommend either ignoring or toggling off predictions in the Fitbit app. The app allows you to choose your current birth control method as well.

Outside of the designed menstrual cycle tracking features, I want to highlight resting heart rate as a potential exciting thing to track for those who are not taking hormonal contraception. Why do you need to not be taking hormonal contraception to utilize the heart rate feature for menstrual cycle tracking? Hormonal contraception suppresses ovulation, and ovulation changes our heart rate charts!

To learn more about resting heart rate and the menstrual cycle, read my previous post here.

You can see my heart rate falling during menstruation around April 10th, and then rise during my fertile window and luteal phase.
Menstruation began when my heart rate dipped below 70 on this chart. Ovulation likely occured around the third raised heart rate in this close-up.

Heart rate in people who are ovulating is at its lowest point during menstruation, rises during the fertile window, and continues to be elevated in the luteal phase.

When heart rate begins to drop again, this is an excellent way to predict menstruation will soon occur. For example, I have been tracking my heart rate in Fitbit for 2 years, and I always bleed when my heart rate dips back down to 70 beats per minute after my luteal phase!

I do think this feature is worth tracking for anyone interested in a more precise period prediction than cycle length. If you have Fitbit premium, you can also find a setting for sleeping heart rate under restoration. This may be more steady than resting heart rate for some individuals.

Lastly, I want to address Fitbit temperature for menstrual cycle tracking. Unfortunately, wrist temperatures are not a compatible parameter for fertility awareness when it comes to avoiding or achieving pregnancy. It can be incredibly erratic. When we track temperature, we want the temperature as closest to the core as possible.

Fitbit does not give precise temperatures, instead it gives deviations from a range. I likely ovulated near 18, 19, or 20 on the photo above. While Fitbit did detect a slight shift, it is not particularly clear, and it dropped back down.

As depicted above, my luteal phase the previous month was extremely undefined, and I could not determine a confirmed temperature shift with it.

For now, I do not recommend Fitbit for precise temperature tracking. Instead, I recommend a basal body thermometer.

Conclusion

Fitbit offers some really unique options for cycle tracking, but it should not replace your birth control or fertility awareness method. The heart rate feature may be useful for identifying cycle phases, but the temperature readings are not suitable for tracking cycle phases.

6 Cycle Comparison: Marquette Versus Billings Versus DOT Fertile Windows

Have you ever been curious what your fertile window would look like in multiple methods?

In this blog, I show 6 cycles with various fertility signs and method interpretation including: the sympto-thermal method (Sensiplan rules), Marquette method, the Billings Ovulation Method, and DOT (a calendar method that was recently purchased by Clue app and is a new FDA approved birth control). I chose to include representation for only studied methods of fertility awareness: sympto-thermal, sympto-hormonal, mucus-only, and calendar method.

All charts are from the Read Your Body app, a flexible app for all methods that I highly recommend!

Some things to know before reading:

  • Marquette allows sex any time of day within their rules. My calculation rule lasts until the end of day 7.
  • Sympto-thermal method allows sex any time of day during first 5 days of menstruation, but the first safe day in the luteal phase must be used in the evening. My calculation rule is day 5.
  • Billings Ovulation Method allows sex in the evenings only and on rotated days in the pre-ovulatory time of the cycle. Days of bleeding where mucus cannot be observed are not allowed. However, since you can have sex any time of day post-ovulation with Billings, sometimes cycle day 1 is available if you have sex before bleeding occurs.
  • DOT allows sex any time of day within their rules. It automatically opens my window on day 7.

Cycle 53

Consecutive Fertile Window for Expected Abstinence:

Billings: 8 days

Sympto-thermal: 12 days

Marquette: 12 days

DOT: 12 days

General remarks: This is an extremely standard cycle in length and mucus patch (the average person will have a 5 to 6 day mucus patch when charting). I believe this is a great example of what methods would look like for someone of the average cycle length.

Cycle 54

Consecutive Fertile Window for Expected Abstinence:

Billings: 9 days

Sympto-thermal: 21 days

Marquette: 15 days

DOT: 12 days

General comments: My average coverline is 96.8 to 97.0, so regardless of earlier high temperatures and some illness I felt confident marking this coverline and temperature shift. Due to continous long, clear-ish mucus, my sympto-thermal peak was extremely delayed. Billings is a sensation focused method so I was able to mark my peak at an earlier time and have less expected abstinence.

DOT gave me a very risky day on this one. It is possible I could have been ovulating near the safe day. However, that would have only left 9 to 10 days for implantation and I had spotting, so whether this truly could have ended in pregnancy is up in the air. Even with well-timed sex, pregnancy will not always occur.

Cycle 55

Consecutive Fertile Window for Expected Abstinence:

Billings: 6 days

Sympto-thermal: 12 days

Marquette: 12 days

DOT: 12 days

General comments: This small fertile window in Billings might look scary to some, but it is not possible to get pregnant when the cervical mucus plug is truly closed. I have about one cycle like this every 13 cycles. I was also using the Kegg device during this cycle which is placed internally and reads electrolyte levels to determine the fertile window. It gave me the same 3 day dip for a fertile window, so I feel even more confident that those days were truly dry. I am missing temperatures on this one because my thermometer glitched and would not give me readings on these days. Sex day 1 was allowed because menstruation didn’t start until 5pm.

Cycle 56

Consecutive Fertile Window for Expected Abstinence:

Billings: 8 days

Marquette: 11 days

DOT: 12 days

General Comment: This was an extremely heavy period so I had no period days available in Billings. Even though the other methods gave me available days, I couldn’t have used them due to the pain, so ultimately the other methods didn’t really help out on more safe days.

Cycle 57

Consecutive Fertile Window for Expected Abstinence:

Billings: 10 days

Marquette: 14 days

DOT: 12 days

Cycle 58

Consecutive Fertile Window for Expected Abstinence:

Billings: 9 days

Marquette: 11 days

DOT: 12 days

General Comments: Marquette monitor missed my peak on this cycle. It misses peak on up to 10% of cycles. I relied on meeting LH rules instead of the monitor. Sex day 1 was allowed because menstruation didnt start until 1pm.

Reflecting on What’s Best for Me

I’m currently on cycle 59 charting, and I have tried a ton of methods. Right now, my ideal method is Billings and LH tests as a bonus marker.

While it may appear that Billings gives less safe days in some instances, what is most important to me is having the smallest consecutive fertile window. Having less expected abstinence actually makes me more likely to follow the rules. I was completely unsatisfied with only being allowed period sex in the sympto-thermal method because I have period pain issues. That means that I basically had no safe days at all in reality before ovulation with sympto-thermal.

I originally felt very enthusiastic about Marquette method. However, after 6 cycles of using the Clearblue Fertility Monitor, I realized that it always caught my LH surge after the cheap LH tests. In addition, it missing my peak even once is frustrating for the cost of the product. For that reason, I have decided to stop using the monitor when I run out of tests. I can use a 15 cent LH test and get the period prediction aspect (LH is my most steady indicator).

The DOT app tends to give me a risky cycle whenever I ovulate late and have a shorter luteal phase. I do not rely on this for pregnancy prevention. Overall though, DOT has not given me many risky ways. I use it for long-term period prediction, and it is the most accurate period predictor I’ve ever used for planning months in advance.

What to Consider Before Switching Methods

1. Why are you unsatisfied with your current method? Is it the amount of safe days, or is it the routine that you don’t like?

2. Do you have medical needs that could be addressed by another method?

Sometimes the grass isn’t greener on the other side, but if you are like me and can’t have period sex or don’t want to have period sex, methods like Billings without calculation rules will almost always include more safe days if you are dedicated enough to learn the method and chart it accurately.

Folks in irregular cycles like in postpartum time or with PCOS may benefit from more flexible methods without calculation rules

*DISCLAIMER: DO NOT TRY TO LEARN FROM MY CHARTS. MY CHARTS ARE NOT YOUR CHARTS.

A Day in the Life of a Billings Ovulation Method User

Have you ever wanted to know what it is like to chart with the Billings Ovulation Method? This blog attempts to give an overview of what it is like for one individual to chart with the Billings Ovulation Method (BOM) over a single cycle. I go through each day of the cycle and explain my overall charting habits. All times are just approximate. I get personal and discuss some challenges I experience with natural family planning. BOM involves tracking sensation felt at the vulva along with the visible appearance of cervical mucus as a person goes about their day to day activities.

Day 1: Record heavy bleeding. Heavy bleeding feels wet. Done! Users are not allowed to use heavier days in the Billings method when avoiding pregnancy. This is a true day one of a cycle because it was preceded by a Billings peak day.

Day 2: Record heavy bleeding. Heavy bleeding feels wet. Done!

Day 3. Record medium bleeding. Medium bleeding feels wet. Done!

Day 4: Very light bleeding. It is now possible to observe my basic infertile pattern of dry.

8am: I feel dry and see a small amount of blood.

10am: I still feel dry.

8pm: I still feel dry. I see no mucus. Sex is allowed in the evening of this day. We use this day.

Day 5: Extremely light bleeding. Technically this day is not allowed for intercourse since I used the day before and Billings method rotates alternative evenings. We use this day anyway #rulebreaker

Day 6: I feel dry. I do not see anything. I record this day as “possibly fertile” since I broke a rule and used the day before. Every day after intercourse gets this white stamp in the pre-ovulatory time of the cycle.

Day 7: My basic infertile pattern of dry is still there! I notice nothing the entire day in the bathroom and my vulva sensation is dry. Sex is allowed in the evening. I consider my evening 8pm because I go to bed around 9pm on average. We use this day.

Day 8: I feel dry all day and see nothing. However, this day is not allowed since Billings alternates days. We skip this day.

Day 9: I feel dry all day and see nothing. However, we do not use this available day because we are both tired. It happens!

Day 10:

9am: I feel a bit moist. I don’t see anything when wiping in the bathroom.

11am: Still feel moist. I do not see anything in the bathroom.

2pm: Still feel moist. I do not see anything.

4pm: Still moist. Nothing seen.

4:45pm: Walking to my car from work. Still moist!

8pm: Overall observation for the day is moist. I record it. The fertile window has opened. This is known as the point of change.

Day 11:

7am: I feel moist as soon as I walk to the bathroom. I see very scant clear mucus on the tissue.

I do not see or feel anything for the rest of the day.

8pm: Overall observation for the day is “moist, clear”

Day 12:

7am: I feel moist, but see nothing.

10am: I feel moist, but see something white.

8pm: The feeling remains the rest of the day. I record “moist, white” for the day.

Day 13:

7am: I feel dry.

11am: I still feel dry.

1pm: I feel wet sensation when walking to my office. This is a change, so I keep that in mind.

I feel damp the rest of the day. I never see anything in the bathroom. I record “wet” as the most fertile sensation that day.

Day 14:

6:30am: I immediately feel moist.

9am: I see long clear strings when wiping in the bathroom.

11am: I have a wet sensation when walking around.

3pm: I walk around my work place. I still feel moist.

5pm: I see clear strings again.

8pm: I record “wet, clear strings” on my chart.

Day 15:

7am: I feel a gush as soon as I wake up. I do not see anything in the bathroom.

9am: I see scant, clear mucus on the tissue when wiping.

11am: I feel very wet walking around my work place.

1pm: I do not see anything on the tissue.

3pm: I do not see anything on the tissue.

5pm: I feel wet sensation while making dinner.

8pm: I record “wet, clear” as my observation for the day.

Day 16:

7am: I do not feel or see anything when waking up.

9am: I still do not feel or see anything.

12pm: I go for a 20 minute walk. When I get back, I feel slippery sensation. I go to the bathroom and see copious amounts of long, clear mucus.

8pm: I felt slippery the rest of the day. I record “slippery, long clear” on the chart.

Day 17:

6am: I feel dry when waking up.

8am: I don’t see anything or feel anything.

11am: I don’t see anything or feel anything.

8pm: The day was nothing felt, nothing seen all day. I record dry. This means yesterday was my peak day because it was a changing and developing pattern ending in slippery followed by an abrupt dry up to no longer wet or slippery.

Day 18 and Day 19:

I have the same experience as day 17. I pay attention all day and observe no mucus or sensation.

Day 20:

Ovulation is expected to be over and the cervical mucus plug has re-closed for the cycle. Sex is available any time for the rest of the cycle until day one of menstruation occurs. I can chart, but it is not necessary to wait until the evening and observations are less important as sex may interfere at any time.

Day 28: I record heavy bleeding and the rules restart.

Real Talk: Diffulties / Obstacles With Billings Not Seen on the Chart

These are things that I find can be difficul in my own personal experience. I know that people in really long cycles or with other irregularities may have different issues than me.

Challenge One: Alternative evenings only can be a struggle, and it seems even harder for me right before the fertile window opens due to my mood at this time of the cycle. This follicular phase is much longer for me than my luteal phase on average, and this means alternative evenings is the rule for most of my cycle. If someone has a partner with a conflicting schedule, this can especially be offputting. I think anyone who is going to practice this method should consider whether this is practical for their lifestyle.

Challenge Two: Expected abstinence in Billings can be hard, and I have fairly short fertile windows on average. I originally practiced sympto-thermal, and I switched to Billings when I realized that overall consecutive abstinence was much less overall (for my own cycle, Billings: 9 days, Sympto-Thermal: 14+ days). I tend to break some rules still, but this is much more suitable for my fertility intentions level than sympto-thermal.

Look out for my next blog on “A Day in the Life of a Marquette User.”

Disclaimer: Do not try to learn how to chart from this post. Everyone has their own unique cycle and this is just an example of charting with Billings in a regular cycle. Please reach out to me if you would like to learn this method with me as your guide. Alternatively, you can find a teacher here.

In Defense of Mucus-Only Methods (Specifically Billings Ovulation Method)

In the fertility awareness world, there are many misconceptions about mucus-only methods. While I cannot speak to mucus-only methods that I have not trained in, I can speak for what I have learned in training in the Billings Ovulation Method. There is so much history of the development of the method that I cannot touch on everything here. For those wanting to learn more, this document goes over some of the history of the method. Outside of that, WOOMB has many useful links.

First and foremost, the usual criticism leveled at mucus-only methods is that they have a low efficacy rating when compared to the sympto-thermal method. However, this is much more nuanced than it may appear at first glance. Let’s look at the most often quoted study for Billings.

This section of statistics is copied directly from a WOOMB International breakdown found here:

1976-78 an independent trial was conducted by the WHO, in five countries (India, the Philippines, New Zealand, Ireland and El Salvador).

This study had two phases:  
869 couples entered the three-month ‘teaching phase’,
725 couples continued in the 13-cycle ‘effectiveness phase’,
with a total of 10,215 cycles in the entire study.

The teaching phase showed that in the first cycle of charting, 93.1% of women were able to record an identifiable ovulatory mucus pattern denoting fertility, and that by the third cycle of charting, 97.1% of women had an excellent or good interpretation of the method.

The results for the entire study were:
2.2 pregnancies/ hwy    (per 100 woman years)  –  method-related pregnancy rate
22.3 pregnancies/hwy  (per 100 woman years)   –  total pregnancy rate

The total Pearl Index  – 22.3/hwy  comprised:
• Conscious departure from the rules of the method: 15.4/hwy.
• Inaccurate application of instructions: 3.9/hwy.
• Method failure: 2.2/hwy.
• Inadequate teaching: 0.3/hwy.
• Uncertain: 0.5/hwy.”

The first thing you should notice is that perfect use was 97.8%. This is pretty high. The second thing you should notice is that typical use includes people who knowingly broke the rules! All typical use always includes this. This statistic of 22.3% typical use failure is used to scare folks away from mucus only, especially when compared to one specific sympto-thermal trial by Sensiplan. However, the Thyma double check sympto-thermal had a 35% typical use rate in one trial. No method is impervious to bad typical use rates because this is dependent on how open someone is to pregnancy, as well as cultural factors. This is a flaw (depending on your perspective) of all FABM methods; someone can choose to achieve pregnancy because fertility is not suppressed.

The next thing to consider is that the older statistics of the Billings Method were based on a different peak rule, a very similar peak rule to which all sympto-thermal methods have adapted. As Billings continued to develop, the method was strengthened by over 850,000 hormonal assays completed by Dr. Brown which tested estrogen, follicule-stimulating hormone, progesterone, and luteinizing hormone. These tests were matched to Billings Ovulation Method charts. The method has been scientifically validated in over 10 total trials.

As the method was studied, the peak rule was changed to help women recognize patterns of fertility and infertility. They discovered when the specific peak rules were met, a changing and developing pattern of discharge and sensation <more specific rules apply to this>, ending at a slippery sensation felt at the vulva 《with walking sensation》and followed by an abrupt change to no longer slippery or wet, that a woman could detect a false mucus patch build up without the need for temperatures. Because of the science that Dr. Brown, Dr Evelyn and John Billings, and Dr. Odeblad verified through numerous studies, they were able to strengthen the mucus only method enough to no longer rely on temperatures without fear of double peaks. The most recent Billings study in China found a 100% perfect use rate and a 99.5% typical use rate when users were very strictly avoiding and highly motivated with the rules.

In short, the Billings Ovulation Method is very effective and for careful charters does not suffer the problem of false peaks. Again, I have barely scratched the surface of all the trials and science involved. I recommend researching Erik Odeblad and the pockets of shaw for more information.

So why do mucus-only methods get such a bad wrap? In the secular communities, I think there are a few main reasons.

1. The methods must be learned through a teacher. Learning these methods takes dedication and regular live (or online) meetings with a real person. Most folks don’t feel like making this effort or think they can’t afford it. Billings has a policy to never turn anyone away in need. Many do free services or payment plans when asked. There is also a charity associated with Billings that can sponsor Catholic couples to help them afford classes.

2. The next reason is that many sympto-thermal users have fundamental misunderstandings of what Billings is. As a certified sympto-thermal teacher and someone who has read about fifteen books on sympto-thermal, it is dissapointing how much of the original science of fertility and the cervix is left out of our materials. My mind was blown when I discovered how things really work when learning a mucus only. From the pockets of shaw to the functions of the cervical crypts, there is so much to learn that is not included in Taking Charge of Your Fertility. This does a great disservice to sympto-thermal charters.

3. Due to these misunderstandings, they think the method cannot be used by those with irregular cycles. They also may think that a non dry basic infertile pattern is not possible due to a misunderstanding of the science of the cervical plug and the effect of estrogen in the vagina.

Potential Cons of Mucus Only:

I do not say any of this to say that the Billings Method is right for everyone. It takes dedication and a willingness to follow the rules if strictly avoiding pregnancy. In addition, there are a few cons to mucus only.

1. A yeast infection or bacterial vaginosis would obscure observations and cause abstinence. However, arguably even a sympto-thermal user would need to abstain when they have an infection.

2. Women who are careless with mucus observations may end up with an unintended pregnancy. If you don’t want to track mucus carefully, this is not the right method for you. If you can’t follow the rules to safely have intercourse, such as evenings only during basic infertile pattern on alternate evenings in the pre-ovulatory time of the cycle, this method may be too restrictive for you.

3. A weak mucus patch that does not fulfill the stringent peak rules may cause more abstinence without a temperature shift to confirm. However, this often signals a potential health issue and should be investigated.

4. Mucus only methods do encourage abstinence when avoiding pregnancy. However, most sympto-thermals do the same. Anyone who is okay with an elevated risk due to barriers or alternative protected sex can always do what they want to do but should be prepared to face the consequences if a barrier method fails.

Conclusion:

Mucus only methods can be highly effective choices for avoiding pregnancy. Recent trials of Billings consistently show 99% or better with perfect use. In some cases, they may reduce abstinence because they allow women to identify false mucus build ups that do not lead to ovulation and non-dry basic infertile patterns. For women who want to eliminate barrier method usage, they offer a way to identify fertility in real time when in irregular cycles due to PCOS, postpartum, or perimenopause. This eliminates much of the extended abstinence or barrier method usage that sympto-thermal users may experience.

Why did I choose to become a fertility awareness instructor?

Why did I choose to become a fertility awareness educator?

Fertility awareness is the sex education I wish I learned in middle school.

When women actually learn how their fertility works, they learn that getting pregnant is not as easy as the drop of a hat. We learn to appreciate and live with rather than work against our fertility.

Almost every person who I’ve seen read #takingchargeofyourfertility or take a FAM class comes out of the experience saying, “Why have I not always known this information? I wish I could have known this when I was younger!” Learning fertility awareness changed my life, and I know it can change yours too.

Do I believe FAM is the right method of birth control for every woman?

No, it is probably not.

But I do believe that every woman should be taught how to understand her own body. What she does with that information is up to her.

Fertility awareness gave me the ability to avoid pregnancy on my own terms. It gave my spouse more knowledge about my body and the changes I experience during my cycle. It has strengthened my relationship in more ways than I can name.

If you want to learn FAM, I suggest getting an instructor. Check out this website for a list of instructors.