Your first menstrual period is called menarche (say "MEN-ar-kee"). It usually starts around age 12. But it may start earlier or later. See your doctor if you have not started having periods by age 15. Your period is a part of your menstrual cycle. This cycle is a series of changes your body goes through to prepare for a possible pregnancy. Menarche also means that you can get pregnant if sperm fertilizes an egg through sex.
Starting your period
In the days before you start your period, you may feel tense or emotional. You may gain water weight and feel bloated. You may have pain (cramps) in your abdomen, back, or legs that lasts a few hours or more. Your breasts may be tender, and you may get acne.
When you start your period, you'll notice a spot of blood on your underwear or when you use the bathroom. The flow of blood from your vagina is usually light at first and may get heavier for a few days before tapering off. The blood may be a brownish color at first and then turn brighter red. Your period will usually last 3 to 7 days each month.
Use tampons, pads, or menstrual cups for bleeding. Ask someone you trust if you have questions about how to use them. Tampons and menstrual cups are placed inside your vagina and are good to use when you swim or do other physical activities. A pad has adhesive strips that help it stick to your underwear. You'll need to change tampons and pads regularly. Having a period won't prevent you from doing any of the activities you normally do. And no one will be able to tell when you're having one.
If you have cramps with your period, regular exercise, a heating pad, a warm bath, and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen may help. Be safe with medicines. Read and follow all instructions on the label.
Keep track of the day you start your period each month. This can help you predict when you'll have your next period. It's also useful when you talk with your doctor.
Your menstrual cycle
Your period is part of your menstrual cycle, the time from the first day of your period to the first day of the next period. A normal menstrual cycle for teenagers can be anywhere from 21 days to 45 days.
For the first year or two, your cycle may not be regular and you may not have a period sometimes. If you are underweight because of dieting or exercise, have a lot of stress in your life, or are overweight, your periods may be hard to predict.
Your menstrual cycle makes it possible for you to get pregnant. Sometime around the middle of each cycle, you will ovulate, which means one of your ovaries will release an egg. You may have a slight discharge from your vagina or some spotting of blood when you ovulate.
You are most likely to get pregnant if you have sexual intercourse on the day of ovulation or on any of the five days before it.
You should assume you can get pregnant any time of the month. The timing of ovulation is different for everyone, especially those who have periods that don't start at the same time every month.
Don't rely on your friends' advice about how and when you can get pregnant. Talk to a health professional—your doctor, school nurse, or nurse practitioner—and parents, if possible, for reliable information about preventing pregnancy and sexually transmitted infections.
Sex and pregnancy myths
The following is a list of myths about sex and pregnancy:
You can't get pregnant the first time you have sex.
Getting pregnant has nothing to do with how many times you have sex. If you are near the time of ovulation when you have sexual intercourse, you can get pregnant.
You can't get pregnant if you're very young.
If you have started your periods, you can get pregnant, even if your body is not mature enough to handle the stress of pregnancy. Girls age 10 or 11, or even younger, have become pregnant. You can also get pregnant in the month before you start your first period.
You can't get pregnant if you have sex standing up.
Position has nothing to do with getting pregnant. The egg and sperm can move no matter what position your body is in.
You can't get pregnant if you have sex during your period.
Although the chance of getting pregnant at this time is less for most women, if you have short cycles (less than 28 days) or irregular periods, you may be able to get pregnant if you have sex during your period.
You can't get pregnant if you have sex in a hot tub.
If you have unprotected sex, you can get pregnant, regardless of where you are.