Period time: It starts on the first day

It starts on the first day of your last period and ends on the first day of your next period. Though the average cycle is 28 days long, anything between 21 and 34 days is considered normal.... Learn about periods, the release of blood from a girl's uterus, and how they relate to ovulation, pregnancy, and menstrual cycle. Find out how to deal with period blood, cramps, PMS, and when to call the doctor. Learn how to track your menstrual cycle and what to do about irregularities. Find out the causes and effects of menstrual cycle changes, such as period time, flow, pain and more. Getting a period is a natural and healthy process, when women shed their uterine lining. Learn how long a “normal” period lasts and how to manage period pain.