You’ve probably heard it called all sorts of things (the rag, the curse, your Moon time) but menstruation is the proper word for what is commonly called your period. When you menstruate, your body sheds the lining of the uterus or womb. People call it ‘bleeding’ but what comes out is actually a mixture of blood, mucus and tissue from the uterus.

Your period is only one stage in a larger cycle of changes that your body goes through regularly to prepare for pregnancy. A woman’s menstrual cycle is counted from the first day of her period to the first day of the next one. The first day of bleeding is called Day 1 of your cycle. Periods are not completely predictable to start with. Eventually, most women will bleed again on day 28 but cycles can range from 21 to 35 days in adults and 21 to 45 days in teens. If you want to know when to expect your next period, keep track on a calendar so that you can figure out what’s normal for you.

About once a month an egg (ovum) is released from the ovaries and travels down the fallopian tubes towards the uterus. This is called ovulation. At the same time, two hormones called estrogen and progesterone are telling the uterus to build up its lining with extra blood and tissue in order to make a cushion for the potential of a fertilized egg. If the egg meets with sperm in the fallopian tubes and a woman gets pregnant, the egg will implant into the thickened uterus lining and continue to develop. If the egg is not fertilized and the woman is not pregnant, her hormones drop and the uterine lining breaks down so it can be shed out the body along with the unfertilized egg. Then the cycle starts all over again.

Did you know that girls are born with all the eggs they will ever have? When the supply runs out or gets too old, your hormones change again and tell your body to stop releasing eggs.

The lining of the uterus builds up every cycle in order to prepare for pregnancy. If there is no fertilized egg (in other words you are not pregnant) there is no need for the thickened uterus lining so the body cleans things the uterus out and the cycle starts over again.

Most girls start menstruating somewhere between ages 9 to 16 years old. ¹ This is a fairly big deal to girls because it signals that they are able to get pregnant (whether they are ready to or not).

You will probably get your period until you are somewhere between 40 to 50 years old. After that you go through another big change called menopause [link to Menopause in the “Sexuality and Aging” section] when your period will stop. Prior to menopause, a missed period can mean you are pregnant, you don’t have enough body weight or that you are exercising too much. Some medication may also interfere with menstruation. Either way, you should probably check with your doctor if your period stops and this is unusual for you.

Again this varies from person to person but normally there is 21 to 35 days between periods of bleeding. Some women have very regular periods and can pinpoint when the bleeding will start within a day or two; other women have irregular cycles and may even skip the occasional month. It is normal for teenagers to be irregular as their bodies adjust to all the hormonal changes. As you get older, your period will probably become more regular and more predictable.

Every month, your body gets ready for a possible pregnancy by releasing an egg from your ovaries. If the egg is fertilized with sperm, it will attach itself to your uterus and eventually develop into a baby. If the egg isn’t fertilized, your body will get rid of any extra tissue and blood that is now no longer needed (you’ll have your period) and the menstrual cycle will begin again.

Usually bleeding lasts anywhere from two to eight days depending on the person. The first day of spotting is the first day of your menstrual period. It is normal to have just a bit of spotting when a person is young and starting to get regular periods. As you get older, the bleeding will probably get heavier and last for an entire week.

Although it can feel like there is quite a bit of fluid coming out, the body only releases one to two fluid ounces (about the amount of a shot glass) for each period. Some females start off with spotting and a light flow that gets heavier as the period progresses; others start off with a heavy flow that trails off.

Menstrual blood is usually thicker and darker in colour than normal blood you might see from a cut. That’s because it is mixed with tissue from your uterine lining. At the end of your period it might look quite brown in colour.

Yes, just prior to menstruation, you body produces hormone-like substances called prostaglandin which signal the uterus to contract in order to help shed its lining. Things like cramps, acne, moodiness and a bloated feeling are also affected by changes in your hormone levels. Some symptoms happen before your period (premenstrual) and some come with your period.

Simply taking good care of yourself will counter some of the negatives that accompany your period. Avoid salty food – which makes your body retain water, and get plenty of exercise - which improves blood flow. Over-the-counter pain killers that contain ibuprophen (like Advil or Motrin) can also help. If the symptoms become painful and stop you from getting on with your day, talk to your friends, a parent, a person you trust or your doctor for more advice. ²

Whether you decide to use a cup, tampons or pads is entirely up to you. Because cups and tampons involve inserting something into your vagina, you may need to experiment with how to insert them and what size you feel comfortable with. Tampons and pads are probably the most common because they are disposable and easy to use. Many women use a tampon and a panty liner to make sure there is no unexpected spotting on their clothing.

Pads come in different sizes and thickness. Use thin pads when the flow is light and thicker overnight pads for times when your flow is at its heaviest.

Tampons also come in different sizes but in general, they are about the same size and shape as a finger. To use a tampon, insert it into your vagina using an applicator or your finger. To remove a tampon, just pull the string attached and throw it or flush it away. If you have trouble inserting a tampon, start with the smallest size and ask someone you trust to help you. You need to make sure it goes into the opening to your vagina and you have to push it in far enough so it fits inside the space near the cervix. To help with insertion, try standing with one leg up on the side of the toilet. Tampons need to be changed every few hours in order to avoid infections. You can wear one overnight but you need to change it first thing in the morning.

For more environmentally friendly products, try a menstrual cup (the “Keeper” or the “DivaCup” for example) or a natural sponge. Most community health stores carry them. To insert a menstrual cup, squeeze the sides and insert it into your vagina. It will fit into the area surrounding your cervix just like a tampon and collect the blood that flows out. To empty it, just pull rubber tail at the end. Wash it with warm soapy water and it is ready to be used again. The sponge is also inserted into the vagina where it absorbs menstrual fluid. The menstrual cup can be left in the vagina for up to 12 hours at a time but the sponge has to be removed and washed every 3 hours.

Talk to your friends, a parent or a woman you trust about what products they use. What ever method you choose, keep a back-up in your bag, especially if your periods make a habit of being unpredictable. ³

PMS stands for “premenstrual syndrome”. The week before prior to menstruation, some women feel irritable, angry, depressed or anxious. These mood swings are normal and caused by a drop in hormone levels at this phase in the menstrual cycle. Other physical symptoms of PMS include tender breasts, bloating, headaches, tiredness and pimples. If your PMS symptoms are severe, talk to your doctor about treatment options. Some females take a very mild birth control pill to help regulate their hormones and control their PMS.

Keep track of when your period starts by marking a red dot or a “P” on the calendar. It will help you get familiar with your cycle and be prepared with menstrual supplies so you aren’t caught off-guard.