Over the last several months, I have been testing multiple femtech products (such as Daysy Fertility Tracker, Kegg, DOT) and comparing them to charting methods like Marquette, Billings Ovulation Method, and Sympto-Thermal (NFPTA). These products and methods rely on different fertility signs such as basal body temperature, cervical mucus, urinary hormones, electrolyte levels, and calendar dates.
Disclaimer: Do not attempt to learn to chart using this post. My own experience may not reflect your unique cycles. My fertility intentions may not be your intentions.
Keep in mind that different methods may change safe days over time. The following data is only a snap shot of what fertility windows for avoiding pregnancy could look like. In particular, the Daysy thermometer only has 4 cycles of data on me.
Expected Consecutive Abstinence Over 3 Cycles
- Billings Ovulation Method: 15 (9 consecutive)
- Marquette: 13
- Sympto-thermal: 16
- DOT: 12
- Daysy: 15
- Billings Ovulation Method: 14 (8 consecutive)
- Marquette: 13
- Sympto-thermal: 13
- DOT: 12
- Daysy: 14
- Billings Ovulation Method: 16 (9 consecutive)
- Marquette: 15
- Sympto-thermal: 19
- DOT: 12 (EXTREMELY RISKY)
- Daysy: 15
From this data, you can see that sometimes the amount of expected abstinence does not differ from method to method, and sometimes it differs a whole lot! On my last cycle with DOT, it ended my avoidance window on the day after peak fertility occured. Fertility is still potentially high on the 3 days following this date.
Billings method almost always had the least consecutive abstinence because it relies on real-time fertility signs to open the window. However, because it rejects calculation rules and relies on one primary sign, only alternative evenings are ever allowed for pre-ovulatory sex. In addition, heavy days of menstruation are not allowed due to the possibility of early ovulation, and the bleeding obscuring the opening of the fertile window.
Other methods like Daysy, Sympto-thermal, DOT, and Marquette do allow pre-ovulatory consecutive sex, but most of that falls during menstruation for my cycle ranges (25 to 30 days).
Whatever method works best for someone is very dependent on their lifestyle and what someone is willing to diligently track.
The Same Chart Seven Ways
The highlighted days represent days to not use in order to avoid pregnancy with these methods.
My hearts are left on to show the fertile window and for authenticity. Do not use these charts to try to learn the rules of any method or to determine when sex is safe. You will see some broken rules based on my own personal intention level and on the fact that not all fertility signs will show the same window.
Unfortunately, my Mira Fertility sticks were flawed, so I had to remove that data from this experiment. In the future, I will do a comparison post also using this device. I am currently still testing the Kegg device, and a review with full Kegg charts is forthcoming in December. Kegg cannot be converted to display on the Read Your Body app, so I could only include the fertile days in this post.
Do you have any questions about all of these methods?
Consider coming to my free Instagram Live on femtech on November 28th. You can find me @chartyourfertility.
On December 12th, I’m offering a “pay what you can” introduction session that is minimum $5 to $30 USD on regular FABM methods and what the main differences are. Reach out to me if you would like to come.
Finally, a special shout to the Body Literacy Collective and the Read Your Body app for making this post possible by creating the most versatile charting app on the market!