Your Menstrual Cycle, Explained

A menstrual cycle usually lasts 21 to 35 days, and a period usually lasts 2 to 7 days. In the first years after periods start, cycles are often irregular, and that's normal.

Keep track of your period dates, use clean pads and change them often, and keep yourself clean.

See a doctor if your periods are very painful or heavy, or stop for a long time.