A girl's period, also known as menstruation, begins after she reaches puberty. Girls usually get their first periods between the ages of 10 and 16, which is about 2 to 2-½ years after their first signs of puberty (breast development is usually the first sign of puberty, but sometimes pubic hair comes first). However, some girls start puberty a little earlier or later than others, which is still normal.
A clue you can use to figure out when you might get your period is to check your underwear for vaginal discharge. This clear or whitish, mucus-like discharge usually appears about 6 months before the first period does.
You can also ask your mom how old she was when she got her first period. Girls who get their first period later than average often find that their moms or other female relatives also went through puberty later than average.
Just because you're 14 and haven't gotten your period yet doesn't necessarily mean that anything's wrong with you. Some girls, though, may not be getting their first periods for other reasons. Girls who are underweight or who have eating disorders such as anorexia nervosa may notice a delay in the beginning of their periods. Girls who are very athletic may not get their periods until they stop exercising or competing so vigorously. Severe stress or certain illnesses also can delay menstruation.
It's also possible for a girl to get pregnant before she gets her first period.
If you have questions or concerns about when you'll get your period, you should talk to your doctor.