Understanding your menstrual cycle is imperative for being able to get and stay pregnant. Your menstrual cycle is often called a vital sign – meaning that it is very important and a tell-tale sign of your overall health. Changes to your cycle can help determine your overall health as well as give us important information about your fertility and chances of conceiving.
There are 2 main phases of your cycle, which are separated by ovulation (the release of an egg from its follicle). The first phase is the follicular phase which is day 1 until ovulation. Ovulation typically occurs mid-cycle, but not always on day 14 contrary to what many of you may have been taught. While ovulation typically happens around the same day each cycle (if you have a regular cycle), it’s important to still learn how to predict ovulation.
On day 1 your estrogen and progesterone have dropped and signaled the start of your period, which is the shedding of your uterine lining (also known as your endometrium). As early as cycle days 2 to 3, your body is prepping for a possible pregnancy as FSH (follicle stimulating hormone) rises, triggers the ovaries to produce estrogen, and causes 15-20 follicles to begin ripening in preparation for ovulation. The follicles each also produce estrogen. Estrogen continues to rise throughout the follicular phase and stimulates the growth or the uterine lining to prepare the uterus for implantation. The spike in estrogen tells your body to reduce FSH (so no more follicles are produced) and triggers the pituitary gland (in your brain) to release LH (luteinizing hormone). This surge in LH is what triggers ovulation.
Ovulation is when the egg is released from its follicle and makes its way through the fallopian tubes toward the uterus. The egg has only about 12 hours (possibly up to 24 hours) that it can be fertilized by the sperm.
After ovulation we move into the luteal phase. The ruptured follicle (that previously housed the egg) is now called the corpus luteum. The corpus luteum is what produces progesterone (and some estrogen) in preparation for pregnancy. Progesterone plays an important role in making you feel calm and in a good mood and generally helps prevent PMS symptoms. During the luteal phase (after ovulation until day 1 of the next cycle), progesterone is the most dominant hormone and tends to peak about 5-7 days after ovulation.
If the egg was fertilized it can now implant into the uterine wall and pregnancy will ensue or if the sperm didn’t fertilize the egg, your hormones will start to drop and trigger your period to start again.
While you don’t necessarily need to know all the hormonal changes throughout your cycle, it is important to understand the basics of your cycle. It’s good to track your cycle so you know the length of each of the phases. If your luteal phase is too short (typically <12 days) you may have trouble getting pregnant, Also, symptoms throughout your cycle may correlate with hormonal imbalances which may be hindering your ability to get pregnant easily. You can take the free hormonal health quiz to help you narrow down what your symptoms may be telling you!