Is It To Be Concerned About The Spotting After Mirena Being Fitted?

well i had the mirena put in in oct 09 and i spotted for over a year afterwards, i havent been having periods besides about two months ago, then about two days ago i started spotting this horrible blackish brown blood....i've had pains like menstural cramps but nothing too serious.. i have no insurance or money and im scared wat could it be