Im a 16 year old female and at about 1pm i suddently started getting pain all across my lower back when i move. Im on the depo injection i have my next one in two weeks but ive been discharging brown and abit of blood (My gp said it was fine) so for the past 3 days ive been using tampons until i started getting pain in my back so i stopped using them just incase. I was wondering if you could help me in what i should do, thank you