You should call your doctor if vaginal bleeding lasts more than seven days, since it may be a sign of a serious condition. Watch Dr. Oz talk about vaginal bleeding and endometrial cancer.
See your doctor about your period if:
You have not started menstruating by the age of 15. You have not started menstruating within 3 years after breast growth began, or if breasts haven't started to grow by age 13. Your period suddenly stops for more than 90 days. Your periods become very irregular after having had regular, monthly cycles. Your period occurs more often than every 21 days or less often than every 35 days. You are bleeding for more than 7 days. You are bleeding more heavily than usual or using more than 1 pad or tampon every 1 to 2 hours. You bleed between periods. You have severe pain during your period. You suddenly get a fever and feel sick after using tampons.
This answer is based on source information from the National Women"s Health Information Center.
Continue Learning about Menstruation
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.