You know, I'm not sure what the world record is for youngest person to start her period -- but I do know there's a huge range. I know girls who started at age 8 or 9 and girls who started at age 15 or 16. I got mine somewhere in the middle -- at age 13. Usually, your period coincides with other changes in your body, so you might get a general idea of when it will happen. Sometimes, though, it's a total surprise! See what Sandy, our health expert, has to say from a medical perspective.

Most girls get their periods somewhere between the ages of 9 and 16. But it's not unheard of for a girl's period to start before age 9. Rather than age, you can look for signals in your body. Most girls don't get their period until they weigh at least 100 pounds and have started developing breasts.

Typically, any period before the age of ten, or puberty changes like breast buds or having physical or emotional changes before the age of eight, is considered something called precocious puberty (starting puberty too early). Developing breasts, pubic hair, behavior changes or having a period could all be signs of precocious puberty. There could be an underlying reason for this to happen, but often there is not. When you see these physical changes or notice any behavioral changes in yourself or your daughter that you would not expect at a young age, make an appointment to talk to your health care provider to talk about your concerns.