The menstrual cycle
WHAT IS A PERIOD?
A “period” is when – once every month or so – blood passes out of a woman’s vagina for a few days. This is normal and all part of being a woman. The medical term for getting your period is menstruation or menses. Your period itself is part of a bigger cycle that goes on inside your body every month as it gets ready for a possible pregnancy.
WHAT’S GOING ON IN THERE?
As you enter puberty your body starts to change. Your breasts develop; you start to get pubic hair and hair under your arms; a few months before your first period you may even notice that you have a clear discharge from your vagina. Don’t panic! This is all normal.
About once a month, an egg leaves the ovaries and travels down the fallopian tubes towards the uterus. At the same time, the lining of the uterus becomes thicker with extra blood and tissue to make a cushion for a potentially fertilized egg. If an egg is fertilized with sperm and you become pregnant, the fertilized egg will attach itself to your uterus where it will slowly develop into a baby. If the egg is not fertilized, the lining of the uterus begins to break down so it can be shed (along with the egg that was not fertilized). Your period – or the time of bleeding – happens when your body gets rid of the extra blood and tissue that’s no longer needed. Then the cycle starts all over again.
The menstrual cycle is your body’s way of preparing itself for a possible pregnancy. Your hormone system controls your menstrual cycle. Things like cramps, moodiness, and your period itself are affected by changes in your hormone levels.
Having periods is a sign that your body may now be ready to have a baby (although you probably aren’t ready just yet!) Your periods will normally continue until you are in your 40s or 50s. That’s when most women stop ovulating (releasing an egg) and stop having their periods. Other times your periods may stop are if you are sick, if you are not eating well or exercising a lot, or if you are pregnant.
WHAT IS A CYCLE?
A menstrual cycle is the length of time it takes your body to go through the process of releasing an egg, preparing the uterus to cushion a fertilized egg, and then shedding the thickened lining and the unfertilized egg (by bleeding that comes out of your vagina).
The first day of your period is called Day 1 of your cycle. Your cycle is counted from the first day of bleeding in one month to the day prior the first day of bleeding in the next month. Keeping a calendar will help you to know when to expect your next period.
For example, if your period starts on the 1st of the month, you have 5 days of bleeding, and then you don’t have another period until the 30th of the month, then you would say that you have a 29-day cycle. Honest, it’s not that confusing!
To learn more about the different stages of the menstrual cycle, see the Periods section.
EVERYONE IS DIFFERENT
HAVING YOUR FIRST PERIOD
You probably have friends who got their period before you and others who haven’t had theirs yet. Every girl is different and this is perfectly normal. Some girls start to menstruate as early as 9 years old, while others don’t start until they are 16, or even older. However, if you haven’t had your period yet by the time you are 16, it’s a good idea to talk to your doctor.
UNPREDICTABLE!
Remember, when you first start your period it will probably not be regular. This is normal! When a woman is older, a regular cycle is about 28 days, but it can be as short as 21 days or as long as 35 days.
For the first couple of years that you menstruate, you may find that your cycle is all over the place, or you may settle into a pattern that is very predictable. Some girls know that their period will come every 28 days, and they can count on it. Others find that they have 28-day cycles for 2 months, then skip a period, and then have 2 periods really close together. As you get older, your periods will normally become more regular which will help you know when your period will come.
Keep track of when you get your period. You can just mark it on your calendar with a red dot, or keep a special calendar to track your period and any other symptoms you might have just in case you want to talk to a health-care professional about your cycle.
Remember, you can still get pregnant if you have unprotected sex while you are menstruating. And if you are having sex without birth control and you don’t get your period for a month or longer, you could be pregnant.
WHAT’S NOT NORMAL?
If you haven’t started your period by the time you are 16, talk to your doctor.
Other reasons to talk to your doctor are if:
- you have a lot of pain or cramping with your periods
- your periods often last for more than 7 days
- your periods are really heavy (if, for example, you have to change a pad or tampon every 1 or 2 hours or you pass lots of clots)
- you bleed between your periods
- you have emotional or physical symptoms (cramps, nausea, depression, irritability) that interfere with your daily life and are linked to your cycle
- your period is late (and usually isn’t) or you haven’t had a period for more than 6 months
- you think you might be pregnant
To learn more, check out www.sexualituandu.ca, administered by SOGC