Yes, i am currently on the implanon birth control implanted in my arm . my last month for birth control is 10/28/12. i have been on this birth control for almost 3 years. about four days ago i was cramping really, really badly, and i was spotting dark brown almost black blood . of course i immediately took a pragnancy test, but it was negative. i took the test because i am having pregnancy symtoms. as long as i have been on this birth control, i have not ever had this problem. what could be the problem, and what should i do?