Charting 101 - Lesson #7: Peak day
In this lesson on the Fertility Awareness Method we discuss an important concept when interpreting your cervical fluid: the peak day. As always, to learn more please read the book Taking Charge of Your Fertility.
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It’s now time to learn what a peak day is. This is Charting 101, lesson #7.
After you finish your period and begin to approach ovulation, your estrogen levels rise. This rise in estrogen is meant to thicken the walls of the uterus and also enable the growth of the egg follicles that will eventually lead to ovulation around mid-cycle.
An important effect of increasing estrogen is that your cervical fluid, if you observe it with your fingers, will go from dry to sticky to creamy to eggwhite in consistency. Measuring this change in cervical fluid is what allows the Fertility Awareness Method to tell when the fertile window has begun.
Once ovulation occurs around mid-cycle, your estrogen levels drop off, and with it your cervical fluid will also dry up. This last day of eggwhite cervical fluid is called your Peak Day, and is an important point in your cycle because it signifies the day when your estrogen was highest, and usually occurs the same day or a day or two prior to your temperature shift. Your peak day thus corresponds with just before or on the same day as ovulation.
Remember, ovulation is a hidden event and you won’t be able to see it unless you do daily serial ultrasounds, but we can get clues because it almost always occurs sometime between your peak day and temp shift. Your peak day also plays a key role in the two Fertility Awareness Method rules that are used to close the fertile window (the Peak Day rule and the Thermal Shift rule).
We will get into what those rules are in a future video. Isn’t your cycle interesting?
Follow along for more Charting 101. Next, we’ll go over what a thermal shift is. And if you’re ready to start charting, download Cyclisity.
As a legal disclaimer, I want to add that this blog post is about the Fertility Awareness Method, not Cyclisity. Cyclisity is an app that helps women chart their cycles but is for informational and educational purposes only. It is not FDA approved as a medical device and does not provide any medical advice. Please consult your physician with any health questions you may have.