Why Cyclisity Applies the Four FAM Rules and Avoids Predictions

The fertility tracking space is full of predictions.

Many apps estimate ovulation using averages, complicated algorithms, trend forecasting, or blackbox "AI insights". They tell users when they are "likely fertile" or "probably infertile" based on population level data and assumptions about the typical menstrual cycle. Or worse yet, they fertile phases on your charts without ever explaining how they are doing it in the first place.

At Cyclisity, we don't believe in those approaches. We subscribe to the Fertility Awareness Method as taught in the best-selling book, Taking Charge of Your Fertility, whose approach is fundamentally different.

The Fertility Awareness Method has a rich history, and is built around deterministic rules, rooted in a woman's underlying biology and endocrinology. The method does not guess, predict, or forecast what your body might do. Instead, it interprets only the real biological signs your body is actually producing today. Not tomorrow, not a week from now, but today. So each day itself is special and needs to be looked at carefully.

Why is this important? Because a woman's ovulation can be delayed by many different things: illness, travel, stress, etc. You can't know that your ovulation is delayed (or sometimes even skipped) from a population-based model. You have to look at your own biology.

If you have entered the fertile phase based on the Fertility Awareness Method, it's not because of a black-box calculation, a hidden scoring system, or a predictive fertility window generated from population averages. It's because your observation of your bodily signs meet specific Fertility Awareness Method criteria, applied day by day. Those rules specifically are the First 5 Days Rule, the Dry Day Rule, the Peak Day Rule, and the Thermal Shift Rule. We will go into these rules in detail in another blog post.

Some examples of our approach vs. predictive apps:

1. A temperature shift is not confirmed unless your temperatures remain elevated above your coverline during the 3 days following your peak day, signaling the presence of progesterone, released from the corpus luteum post-ovulation

2. Ovulation is not assumed simply because you are on day 14 of your cycle

3. Your peak day can only be recorded once you've actually had a peak in your cervical fluid readings, signaling the natural rise and fall in estrogen during your cycle

We believe the educational benefits of showing a clear application of the four FAM rules on your own data is immense, and part of why we built Cyclisity in the first place. To improve access to the Fertility Awareness Method, we have to improve access to education about FAM and it's practical application.

Our goal is not to automate awareness away from our users, and no user should solely rely on Cyclisity's application of the FAM rules. Read Taking Charge of Your Fertility, apply the four FAM rules yourself, and use Cyclisity as a helpful double-check on your work. This way you can feel confident in your assessment of your own cycles, even when an obscure subrule applies to your particular cycle.

Practicing the Fertility Awareness Method requires recording quite a few data points. Such data points include:

1. Basal body temperature

2. Cervical fluid readings

3. Bleeding observations

4. Temperature shifts

5. Peak day identification

6. Coverline identification

7. Drawing fertile phases

8. Recording intercourse days

9. Optionally cervical positions readings

Organizing this information in a helpful way used to rely on pen and paper, but we've designed Cyclisity to be the next step in helpfulness for FAM practitioners everywhere. Every application of the four FAM rules should feel traceable, explainable, and grounded in the incredible book Taking Charge of Your Fertility.

Fertility awareness is not about predicting the future. It's about learning to properly observe the present.

Disclaimer

Cyclisity is an educational tool designed to support fertility awareness learning. Cyclisity is not an FDA-approved medical device and does not provide medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional regarding medical concerns.