For the past three months I have been experiencing black vaginal discharge during my time of the month. The discharge only happens during this time, and I haven't noticed a foul odor along with it. I don't have any pain along with the discharge either, aside from menstrual cramps. I am taking Lo Loestrin FE birth control, and have 2-3 day periods. There is also no chance of forgetting to remove a tampon because I do not use them. What may this discharge be a symptom of? Please help!