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Progesterone Q + A: The Misunderstood Ovulation Hormone Part 1

by aman | November 17, 2021

Part 1: What Is Ovulation?


Often we meet women who have been mis-prescribed progesterone by doctors who aren’t as familiar with the nuances of fertility medicine and the physiology of ovulation.  If used incorrectly, prescribed progesterone can act as a birth control, rather than support fertility. Unfortunately, this is a common occurrence as there are so many misunderstandings around ovulations and progesterone. This is a huge key to fertility. At Famlee, our mission is to help bring clarity to women’s health and fertility—and that includes the ever-misunderstood ovulation hormone: progesterone. Let’s get started with part one of our three part series… 


How does a monthly cycle relate to ovulation?

The entire monthly cycle is built around maturing a healthy egg for ovulation and then giving the body time to register a pregnancy, if there is one, from that ovulation. In a typical monthly menstrual cycle, there are two phases: follicular and luteal. The follicular phase is the first two weeks of the cycle, when the body is growing the follicle(s)/eggs to prepare for ovulation. For some women, this phase is longer or shorter (as it can take some bodies varying amounts of time to grow a mature egg). The luteal phase (think LH strips – luteinizing hormone) starts after ovulation and lasts about two weeks until the next period comes or you find out you are pregnant. Most luteal phases are 10-14 days, as it takes at least 7 days for the fertilized egg to travel to the uterus after ovulation.   

What is ovulation?

At ovulation, the mature egg(s) literally burst out of the ovary. The egg leaves behind a “scar” called a corpus luteum. This scar produces progesterone, in case you become pregnant from that ovulation, to hold the uterine lining steady until a fertilized egg can implant. In most cases, ovulation happens about halfway through the monthly cycle. In a 28-day cycle, for example, it is common to ovulate around Day 14. This gives around 13 days to grow a nice size egg, 1 day to release it (hoping for fertilization), and around 12-14 days for the fertilized egg to make its way through the fallopian tubes and down into the uterus, where it can tell the body to not bleed. In this case, you are pregnant. 

Does a + OPK mean I ovulated?

No, a +OPK does NOT mean you ovulated; instead it tells you that ovulation is coming soon. Ovulation predictor kits (OPKs), or Luteinizing hormone (LH) strips, tell you when your body gets the green light to ovulate. This happens before ovulation. When the egg is ready for ovulation, the brain releases a spike of LH to tell the ovary to release the egg. OPKs and LH strips measure that spike in LH, which usually happens about 12-48 hours before ovulation. This gives you a heads up to try for pregnancy. 


I got a + OPK.  How do I know if I actually ovulated?  

The only way to know if you ovulated is to look at progesterone around 7-9 days AFTER a +OPK. When the egg is released from the ovary, the literal spot in the ovary where it grew and burst through the ovarian wall produces progesterone and the amount produced rises for the week following ovulation. If there is implantation of a fertilized embryo, the progesterone level will further rise. If there is no implantation, it will drop and initiate the next menstrual cycle.  

Do ovulations change with age?

Yes, they change in many ways. As we age, our egg quality declines as our eggs are more vulnerable to genetic mutations, since they have been exposed to everything in our life leading up to that ovulation. It is also more common for women to release more than one egg with each ovulation, as they age. That is one of the reasons that the risk for multiples can increase as we age, not just because of fertility medications. The length of time from +OPK to ovulation is also thought to change with age. When we are younger, the time from the green light (+OPK) to ovulation is longer—about 24-48 hours for women in their 20’s and early 30’s. This is thought to decrease to a shorter time, around 12 hours, between +OPK and actual ovulation for women in their late 30’s to early 40’s. In some cases, because of a quick OPK surge, it can be good to test LH strips both morning and evening.  


This concludes Part 1 of our 4-Part Progesterone Q+A Series—check back soon for Part 2. Click here for more information on the Famlee Fertility Kit.