What is the menstrual cycle?
The menstrual cycle is the pattern of hormonal and physical changes that drives reproductive function in female bodies. This cycle repeats every month (about 26-35 days, but it can vary!), and is divided into four “phases”. Understanding the phases of the menstrual cycle can help you understand your body, plan for pregnancy, predict your next period, and catch changes to your health early. That being said, there’s a lot that goes on during your cycle, and it can be quite confusing to understand, so we’re here to simplify!
Before we start — remember that the numbers in this article are averages, and may not apply to you directly. Also, if you’re quite young, don’t stress if your cycle is irregular! It takes about eight years after you start your periods for your hormonal cycle to fully mature, and it’s normal for it to be irregular in that time. Generally, your cycle will become more and more regular as you age. If you’re unsure if your cycle is normal, don’t be afraid to ask a doctor!
Menstrual Cycle Diagram: https://helloclue.com/articles/cycle-a-z/the-menstrual-cycle-more-than-just-the-period
Menstrual Phase: Approx. Day 1-5
The menstrual phase starts on “Day 1” in your cycle, which is the day your period starts. How long your period lasts depends on a few factors, including genetics, but is usually 3-7 days. During this phase, your body is shedding the extra tissue in your uterus, which you don’t need because you aren’t pregnant. The amount of actual blood you lose typically less than you might think — about 5-80mL!
Follicular Phase: Approx. Day 1-14
The follicular phase starts at the same time as the menstrual phase, but lasts all the way until you ovulate — usually about 14 days. This phase is dominated by a hormone called “follicle stimulating hormone”, which causes one of the follicles in your ovary to mature and prepare a viable egg. At the same time, your uterus builds up its lining to prepare, in case that egg is fertilized and needs a place to live. At the very end of the follicular phase, your estrogen levels spike, telling your body it’s time to release an egg.
Ovulation Phase: Approx. Day 14
Once the follicle is fully matured it will release an egg, which is what we call “ovulation”. This egg cell travels down the fallopian tubes, where it can be fertilized by a sperm. (Fertilized eggs will stick into the prepared wall of your uterus, where they’ll grow!) It takes about 24 hours for the egg to make its way through your reproductive system, and this time is when you can become pregnant.
Sperm can live in your reproductive tract for up to three days! 3 days before you ovulate, until about 24 hours after you ovulate, is the “fertile window”, aka the time where sex can result in pregnancy. However, ovulation can be hard to predict, so if you’re trying to prevent pregnancy, it’s best to act as though you’re always able to become pregnant — even on your period!
Luteal Phase: Approx. Day 15-28
The luteal phase is the time between ovulation and the start of your next period, and is about 14 days long. During this time, the follicle that just released its egg will transform into the “corpus luteum” — a tissue that produces progesterone, which is the hormone that prepares your body for pregnancy. If you’re not pregnant, the corpus luteum will disintegrate, and the loss in progesterone will start your next period, and the cycle will repeat!
More questions about the menstrual cycle? Let us know!
