How do you know if your period is regular or irregular? I can't figure mine out!
– Laura*

We sometimes use the words "monthly cycle" to describe periods — but that can make it seem as if all periods happen like clockwork every 4 weeks! The truth is, different girls have different cycles.

A girl's cycle is the number of days from the start of her period to the start of the next one. On average, it's 28 days. But cycle lengths vary — some girls have a 24-day cycle, some have a 34-day cycle. It's common for girls to skip periods or have periods come at different times, especially in the first few years after beginning menstruation. Other things that affect cycles include diet, stress, exercise, and, occasionally, illness.

Try not to worry if you can't figure out your cycle for the first couple of years after you start getting your period. Things should settle down eventually. But if your period isn't coming regularly, if it's very uncomfortable or heavy, or if it's stopped, see a health care provider.

*Names have been changed to protect user privacy.