The menstrual cycle is an incredibly important process that governs female fertility and can be a signifier of your overall health. The menstrual cycle is made up of two separate cycles that each run from bleed to bleed. Here’s everything you need to know, from your period to the proliferative phase.  Quick facts: The menstrual cycle: more than just your period When we talk about the menstrual cycle, our periods seem to get all the air time. But the menstrual cycle is far more than that, with our periods only making up a very small part of the whole monthly process. But thanks to cultural stigmas, taboos and limited sex education, it’s no surprise that many of us have grown up knowing very little about the ups and downs of our menstrual cycles.  Not only is your menstrual cycle super important for your fertility, but it’s intimately linked to your overall health. It can easily be influenced by other factors such as stress, diet, weight fluctuations, exercise, sleep, illness and medications. The American College of Obstetricians and Gynecologists (ACOG) has now classified the menstrual cycle as a vital sign—putting it right up there with your heart rate and blood pressure. So yeah, your menstrual cycle is a big deal. Period. What is the menstrual cycle? The menstrual cycle is the bodily process that makes pregnancy possible. It involves a series of natural changes in hormone production that affect the uterus and ovaries.  Your cycle starts on the first day of your period (the first day you bleed) and ends on the first day of your next period. It’s made up of both the ovarian cycle, which affects the ovaries and regulates ovulation, and the uterine cycle, which affects the uterus. Both of these cycles happen in tandem and are carefully regulated by your incredible cycling hormones—oestrogen, progesterone, luteinising hormone (LH) and follicle-stimulating hormone (FSH). What happens during the ovarian cycle? During the ovarian cycle, one of your ovaries will develop an egg which will be released mid-cycle, during ovulation. The ovarian cycle includes three main phases, the follicular phase, ovulation and the luteal phase. Let’s look at each phase in detail. The follicular phase Day 1 of your period is counted as day 1 of your menstrual cycle—it’s also when the follicular phase begins.  For most people, this phase lasts around 10-16 days, ending mid-cycle, around ovulation. (although this can vary from cycle to cycle and person to person). Changes to the length of your follicular phase are usually the main reason why your cycle length may vary from month to month.  During the follicular phase, a selection of immature eggs in one of your ovaries begins to mature. One egg will reach full maturation and be prepped for release during ovulation. The follicular phase kicks off when gonadotrophin-releasing hormone (GnRH) is secreted from your brain, which promotes the release of follicle-stimulating hormone (FSH).  FSH stimulates your follicles—little sacs in your ovaries containing immature eggs, and a few selected follicles will begin to grow and mature. As these follicles grow, they secrete oestrogen—the main female sex hormone.  Thanks to the rise in oestrogen, generally, this time in your cycle you’ll likely be feeling your best, most confident, sexy and unstoppable. Time to schedule that date and promotion discussion.  However, not all of the follicles make it. Only one follicle will be picked as the chosen one for that month and the others will stop maturing. This chosen one is called the dominant follicle and will be prepped for release during ovulation. Ovulation Oestrogen gradually increases during the follicular phase and peaks around the middle of the cycle. This triggers the brain to produce a hormone called luteinising hormone (LH).  A sudden surge in LH levels triggers ovulation, which is when the now mature egg will be released from your ovary.  Ovulation takes place 28-36 hours after the onset of the LH surge. The released egg will travel through the fallopian tubes, where it will wait in hopes of being fertilised by a sperm.   Ovulation usually happens around the middle of your cycle, if you’re having regular periods. This is usually estimated to be around day 14 of your cycle, but this is based on the assumption that everyone has a 28-day cycle, which is not always the case. The date of ovulation can fall anywhere between days 11 to 16 of your cycle. During ovulation, you are at your most fertile. Your fertile window is the 5 days leading up to ovulation and the day of ovulation itself. This is when you’ll be most likely to conceive.  If you’re trying to conceive, or using natural birth control methods, there are a few things you can use to track ovulation.  The luteal phase The luteal phase of the menstrual cycle lasts from the day after ovulation until the day before your next period. It lasts about 14 days and usually, this is the same in each cycle.  After you’ve ovulated, the empty follicle that released the egg will get converted into a structure called the corpus luteum. This will produce a hormone called progesterone, which is important for pregnancy, and small amounts of oestrogen.  Progesterone thickens the lining of your womb, called the endometrium, in preparation for a fertilised egg to implant into it. The endometrium helps to support the growth and development of an embryo. If a sperm-meet-egg moment happens and fertilisation occurs, the corpus luteum will keep growing until the placenta (this is the organ that develops to help the baby get its food and oxygen) can take over the job of producing progesterone.  However, if fertilisation does not happen, the corpus luteum will shrink causing a drop in both progesterone and oestrogen levels triggering your period. This is also the phase during which premenstrual syndrome (PMS) might rear its ugly head.  What happens during the uterine cycle? The uterine cycle happens alongside the ovarian cycle and involves all of the changes happening in the endometrium as it prepares to […]