Nothing happens if you don't get your period at 13 years old. The average age of menarche is 13 years old so if you haven't started menstruating yet that's fine, everyone develops at different times and in different ways - if you still haven't reached menarche by 16 then talk to your doctor. Once you do start getting periods it's normal to have late or absent menstruation throughout your teens.
When you get your period, your body is letting you know you can have sex.
13
Well, you can be any age, but your period usually happens to girls ages 8-13. Here is a tip: don't use it if your not on your period.
13
my teacher says girls get their period when they are around the age of 9 to 16
the gestation period of a female manatee is 12-13 months.
Your period depends on your body. It may or may not be before you're 13
Around age 13 or 14
You normally get your around 13
selena had her period whens he was 12 or 13 one of those ages
it happens at puberty age 9-13
Of the women I know, the age range is 9-14. I was 13 when I started.