This is the Science behind it.
Meet the storytellers of your fertility.
Your hormones tell a story each cycle. Here's how you can listen.
Basal Body Temperature(BBT): A proxy for progesterone. BBT is the most important fertility symptom because it helps you detect ovulation occurred on each cycle. You can detect ovulation once your temperature has risen by 0.1ºF and stays up for three days.
Cervical Fluid: A proxy for estrogen, cervical fluid is responsible for creating the "water" for swimmers. Without it they can't get to the egg. The more stretchy and clear the more fertile the quality of it, which also means impending ovulation.
Period: In addition to BBT and cervical fluid, period length and flow is a key reproductive health indicator.