in my opinion, Doctors consider normal menstrual bleeding a period that lasts from three to seven days; prolonged menstrual bleeding, or menorrhagia, is defined as bleeding that goes beyond a week. Depending on the circumstances, long menstruation may be a condition that can be easily controlled with birth control hormones or one that indicates a serious underlying health issue. possible causes : DUB Uterine fibroids, non-cancerous growths of the uterus wall Endometrial hyperplasia, a thickened endometrium A bleeding disorder, like von Willebrand disease Problems with clotting Thyroid functioning Glandular issues Infection Ovarian cysts Uterine polyps you should consult gynaecologist and give proper history of bleeding like duration , changing cloths per day , pain etc I hope you happy with information, kindly rate it. thank you .