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. Your menstrual cycle is the time from the first day of your menstrual period until the first day of your next menstrual period. Every person’s cycle is slightly different, but the process is the same. How long is a normal menstrual cycle? The average length of a menstrual cycle is 28 days. 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. How long does a first period last? It’s normal for a first period to last 2–7 days and be very light. In fact, you might only experience some red or brown spotting during your first periods. In the US, the average age when people get their first periods is 12–13. Ninety-eight percent of people who get periods start having them by the time they’re 15. Health care providers typically recommend that teenagers have their first OB-GYN visit when they’re 13–15. Most teenagers won’t ...
