I have been on the implanon (in the arm birth control) for a year in January. And the past couple of months I've had horrible pain with my period and this weird brown discharge. This month I've had my period three times. With the brown discharge inbetween. And for the past week I've had pains in my lower abdominal and lower back so bad I can't move and I'm nauseous, and barely eat. Is this caused by my birth control?