How long does a period last and how much time is there in between periods?

Nine out of ten girls have a period that lasts less than a week. The average is 4,7 days. The time between the first day of your period and the first day of your next period is called the menstrual cycle. The average menstrual cycle is 28 days. Some girls have their period every three weeks, while others have it every 5 weeks. Cycles shorter than 3 weeks or longer than 6 weeks are considered abnormal. But once you first start menstruating it’s only a problem if you have your periods very often and loose a lot of blood. But it’s perfectly normal to skip periods, even 6 in a row. Periods often stabilize only after about two years. If you note the day you start your period in your pocket calendar every month you might discover a pattern after 4 or 5 months, knowing when to expect your next period.