Menstrual Disorders Cycle Disorders What to Know About Irregular Periods in Teenagers By Denise Witmer Denise Witmer is a freelance writer and mother of three children, who has authored several books and countless articles on parenting teens since 1997. Learn about our editorial process Denise Witmer Medically reviewed by Medically reviewed by Brian Levine, MD on November 01, 2019 linkedin Brian Levine, MD, MS, FACOG, is board-certified in obstetrics and gynecology, as well as in reproductive endocrinology and infertility. Learn about our Medical Review Board Brian Levine, MD Updated on January 30, 2020 Print Table of Contents View All Irregular Cycles Predicting Your Period Missing Several Periods It is quite common for some girls to have irregular periods during their first year of menstruation. However, it's not normal if she misses her period for three to five months in a row, especially if she has had a period regularly for some months before that. The medical term for not having periods is amenorrhea, and when this condition goes beyond three months, then a trip to see your doctor is usually needed. Parents of teen daughters with irregular periods often ask these questions: Why is my teen daughter's period only once every two months? Or why does she get her period twice a month? Why does it last for only two days one month and 10 days the next? There are many reasons that your daughter may be experiencing irregular periods, listed below are some things both you and your daughter should discuss. Irregular Cycles It is normal for a girl during her first two years of menstruating to have an irregular menstrual cycle. Some women have irregular periods for their entire lives, although most women have a cycle that they can count out. The 28-day cycle that is written about in books and followed by doctors is an average, not the rule. A teen's body is influenced by its growth and therefore can start and stop the menstrual cycle while it's growing. Fluctuating Hormones The length of time in days and the amount of blood of a girl's period is influenced by the amount of hormones that her body is currently manufacturing. Therefore, it is normal for a teen who is growing and has fluctuating hormones for the amount of blood and the length of time her period lasts to be different from one period to the next. Other Factors There are many outside influences that can cause irregular periods, including these: MedicationsSignificant weight gain or lossOver-exercisePoor nutrition (or a diet too high in carbohydrates)Drug useEating disordersIncreased stress If you feel one of these influences may be causing your teen's irregular periods, you should talk to her doctor. Predicting Your Period Teach your daughter to start recognizing the signs and symptoms of her period so she will have an idea of when it is coming. If she has irregular periods, you'll want her to carry a pad with her at all times, as it will be best if she is prepared when she does get her period. You should ask her to mark down on a calendar when her period starts and when it ends. This is important because if her irregular periods become a medical problem you will have the answers to her doctor's questions about when she had her periods and how irregular they were. Missing Several Periods While skipping one month or having a shorter or longer span of days between periods isn't abnormal for a teen, if your daughter's period doesn't show for a much longer amount of time, you'll want to consult her doctor. Pregnancy If your teen is sexually active and skips a period, she should be seen by a doctor to rule out pregnancy. If she is normally irregular she should still see a doctor after two 28-day cycles of not getting her period. A missed period is still a sign of pregnancy even in women who have irregular periods. The development of amenorrhea—absence of a menstrual period for three months or more—should be reported to your teen's doctor as it could be a sign of premature ovarian failure, a condition that fully develops in a woman's 40s. What You Need to Know About Amenorrhea Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. The Nemours Foundation. My Periods Are Irregular. What's Going On? Updated November 2015. National Institute of Child Health and Human Development. What causes menstrual irregularities? Updated January 31, 2017. Rebar RW. Premature Ovarian "Failure" in the Adolescent. Ann N Y Acad Sci. 2008;1135:138-145. doi:10.1196/annals.1429.000