Understanding Your Menstrual Cycle

As its name suggests, the menstrual cycle describes a series of events that are regularly repeated in the same order. Your period is just one part of that cycle. The more you discover about what goes on during the cycle, the more amazed you’ll be by your body.

The menstrual cycle timeline

Day one is the first day of your period and the cycle ends on the first day of your next period. On average, the whole thing lasts around 28 days, but it can be anywhere between 21 and 45 days. Having irregular periods, or fluctuating lengths, is extremely common so, unless you’re having any other symptoms, it’s not something you need to worry about.

The first 10-14 days of the cycle is called the follicular phase. This covers the menstruation period, when the lining of the uterus is shed and passes through the cervix to the vagina and out of the body as menstrual blood. This lasts approximately three to seven days and is the part of the cycle you’ll be most familiar with.

By the way, if you don’t know your uterus from your elbow or your cervix from your cranium (a lot of people don’t), check out our Anatomy 101.

The follicular phase ends when you ovulate, at around day 14 of your menstrual cycle. Your body prepares for ovulation by producing two hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These stimulate your ovaries to produce eggs. They also trigger an increase in the female hormone estrogen. An extraordinary balancing act occurs where each of the hormones works together to ensure one egg begins to mature and the others stop growing. This dominant egg is then released into the fallopian tube in readiness for fertilization. As soon as the egg is released another hormone, progesterone, works on building up the lining of your womb. This is the time when you’re most fertile so, if you’re looking to get pregnant, you want to be having sex in the 24-26 hours following ovulation.

Ovulation kicks off the final phase in your menstrual cycle - the luteal phase. This lasts until your next period and is usually around 12-16 days long. If the egg hasn’t been fertilized your levels of estrogen and progesterone decrease, the thick womb lining starts to break down and, just like the month before, your period will begin.

You may experience Premenstrual Syndrome (PMS) during this final phase. If you’re affected, check out our article on how to deal with PMS.

You can get to know your own menstrual cycle much better by using a period tracker such as Spot On, Cycles, Eve or Clue.