Abnormal bleeding occurs when you have: - Heavier bleeding than usual - Bleeding for more days than normal (menorrhagia) - Spotting or bleeding between periods - Bleeding after sex - Bleeding after menopause - Bleeding while pregnant - Bleeding before age 9 - Menstrual cycles shorter than 21 days - Menstrual cycles longer than 35 days - No period for 3 to 6 months The menstrual cycle is different for every woman and is typically counted from the first day of one period to the first day of the next. Normally, menstrual flow (bleeding) occurs every 21 to 35 days and lasts two to seven days. While long cycles are common for the first few years after menstruation begins, they tend to shorten and become more regular with age. A menstrual cycle can still be considered normal if it is regular (about the same length every month) or irregular, light or heavy, painful or pain-free, long or short. Within a broad range, “normal” is what is considered normal for the individual. Certain types of contraception will alter the menstrual cycle, such as extended-cycle birth control pills and intrauterine devices (IUDs). Talk to a women’s health specialist about what to expect when starting a new contraceptive.