Menstrual cycle

Michael and Lina are watching a film. Ouch, my stomach feels like someone just stabbed me... Lina! You’re bleeding on the sofa! Oh no, my period started!

Why do I have to have periods?! Lina is very embarrassed, but there’s no reason to be! A period, or menstruation, is a natural process and it shouldn’t be embarrassing. Menstruation is part of a series of events that happen regularly in the same order, a cycle, that is all about preparing the body for a possible pregnancy. The cycle is caused mainly by four substances that send different signals around the body, hormones.

These are oestrogen, progesterone, follicle stimulating hormone and luteinising hormone. The day bleeding, or menstruation, starts is considered to be day one of the cycle. Menstruation can last between 3 to 7 days, but on average it lasts for 5 days. During these first few days of this cycle, the levels of the four hormones are low. Once the bleeding stops, the level of oestrogen starts increasing.

This causes tissue lining the uterus, to thicken. Thickening goes on for about 10 days, usually between day 6 and day 14 of the cycle. At the same time, in another part of the reproductive system, the ovaries, an egg cell matures. Around day 14 of the cycle, high levels of luteinising and follicle-stimulating hormones signal to the ovary to release the egg. This is ovulation.

Next, the egg moves into the fallopian tube - the channel that connects the ovary to the uterus. This happens around day 15 of the cycle. If sperm is present in the fallopian tube, it can fertilise the egg. Between days 15 and 28 of the cycle, hormone progesterone prepares the uterus for the arrival of a fertilised egg. The lining of the uterus is kept thick and rich in blood supply to accommodate the egg.

But if the egg is not fertilised the thickened lining of the uterus has no purpose. There is no need to maintain the lining anymore, and the progesterone levels drop. This sends a signal to the uterus to shed its lining. The egg breaks down and exits the uterus together with the shedding tissue. This is menstruation, and is the beginning of a new cycle - the menstrual cycle.

Everyone’s cycle is different. If you have a different cycle than described, that’s okay! Your cycle might be shorter or longer, it might be 21 or 38 days, or vary from month to month. This is very common, especially if you’ve only just started having your period. Differences are not uncommon, but it’s a good idea to observe your body and track your own menstrual cycle.

This can help you notice if there’s something unusual going on, and to prepare if your period is running late, or coming early. If your period doesn’t come “on time”, it doesn’t necessarily mean you are pregnant. It might just be late, or it might be due to other things: illness, stress, dieting, an eating disorder, or even intense exercising. If you feel insecure about your cycle, or if you do notice something uncommon that worries you, don’t hesitate. Talk to a doctor, a midwife, a youth clinic, or an adult you trust.

Do you think you could ask Jenny for some pads and a pair of jeans for me? Sure! Anything you need...