Period time: Why are periods/menstruation cycles irregular in

Why are periods/menstruation cycles irregular in some women? For some women, the time between periods and the amount of blood shed during menstruation vary considerably. Explore detailed guide on menstrual cycles. Understand period time, track menstrual calendar, and know your fertility window. 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. 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.