Hello Hannah, Thanks for posting on HCM, You are obviously suffering from abnormal uterine bleeding and yours seem to be menorrhagia which is an abnormally heavy and prolonged menstrual period at regular intervals. Menorrhagia can be caused by abnormal blood clotting, disruption of normal hormonal regulation of periods, or disorders of the endometrial lining of the uterus. Depending upon the cause, it may be associated with abnormally painful periods (dysmenorrhea) as your case presents. A change in hormone levels is a common cause of abnormal menstrual bleeding (dysfunctional uterine bleeding). What you need to obviously do now is consult a gynobs as soon as possible. A pelvic scan might be requested to determine one of the numerous causes that might be responsible. Hormone analysis will also be done to find out the hormone that is responsible. Hope this helps