Understanding your menstrual cycle

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February 15, 2016
menstrual cycle, naturopathic doctor toronto, toronto naturopath, women's health, periods

I was in grade 6 when I experienced my first menstrual cycle. I really didn’t know much about it, other than it would come every month until I turned 50 (or so). For those of you who’ve blocked that middle school period video (like I did!), I’m going to break down the menstrual cycle for you: its phases, when ovulation typically occurs —  and what that means, and the four hormones you should know about!

menstrual cycle, period

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Follicular Phase

The first part of the menstrual cycle: days 1-14. Day 1 begins on your first day of heavy bleeding. In this phase, follicle stimulating hormone (FSH) acts on some of the ovarian follicles to mature so that one will eventually release an egg. The maturing follicles will produce estrogen, which will suppress FSH as it rises. Around day 10, the estrogen spike will lead to a spike in luteinizing hormone (LH) around day 14 triggering ovulation in the most mature follicle of the ovary.


At day 14 (in those perfect 28 day cycles), there will be a spike in LH. The ovary will release the most mature follicle and will begin its descent to the fallopian tube. If you’re hoping to get pregnant, now is the time to get intimate! Once sperm and egg meet fertilization may occur. Keep in mind that your fertile window lasts a few days before and after ovulation.

Another suggestive sign of ovulation is observing the quality of cervical mucus (usually on your panties or when you wipe). Mucus typically changes throughout the cycle, and when you’re fertile it becomes thick and stretchy, and feels like a lubricant. This makes it easy for the sperm to reach the egg, and even provides the sperm nourishment for its travels! (Women are always taking care of men!)

Luteal Phase

The second part of the menstrual cycle: days 15-28. The formation of the corpus luteum (CL) begins. The CL is the remainder of the matured follicle and sticks around to secrete hormones: estrogen and progesterone. At day 21, progesterone is increased and stimulates endometrial growth. If fertilization has happened, the fertilized egg will travel from the fallopian tube to the uterus and implant in the uterine wall. If no fertilization has occurred, the CL will degenerate causing a decrease in progesterone leading to shedding of the endometrial lining (your period!).

Next Steps

Note: the cycle is a wee bit more complex than this (there’s a few more hormones involves and a couple of glands in the brain), but it’s the general picture.

My absolute favourite way to track my period is Clue. It’s a great way to find how long your average cycle is, when you’re most fertile including the estimated ovulation date, and track any symptoms that you notice during the month (sore breasts, cramps, increased cervical fluid, changes in temperature — important in BBT charting, etc.).

Did you learn anything new about your cycle? Do you have a typical 28 day cycle? If you require support getting off the birth control bill, or are wanting to normalize your period book an appointment with me! PS. For more detailed info, check out this post on how babies are conceived.  

Hopefully you’ve come away with a plan of action! If you love learning about your hormones and your period, be sure to sign up for my monthly newsletter called The Flow for great and informative content like this!

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