Bleeding black after taking birth control pills may be caused by withdrawal bleeding, blood accumulates in the body for a long time, resulting in black color.
Women taking birth control pills, vaginal bleeding belongs to the withdrawal of bleeding, normal menstrual blood color is dark red, bleeding if the uterine cavity to stay longer, not discharged in time when the color will gradually black, generally do not need to intervene. If it persists for a long time you need to consult a doctor for examination, to exclude pregnancy and to clarify the cause of treatment.
Taking birth control pills may cause early or delayed menstruation, prolonged menstruation, and also cause nausea, vomiting and other adverse reactions, these adverse reactions will generally subside on their own, and if you take emergency contraceptive pills several times in a short period of time, it will also cause menstrual disorders, or even infertility. You should consult your doctor in detail before using the pill, and treat any discomfort in a timely manner.