What Causes Lower Back Pains,stomach Cramps And Thick White Discharge?

i got my mirena 3 years ago i have lower back pains stomach cramps i have a white thick discharge is this a serious ive read up on it and everything ive read leads to cancer im kinda worried could it just be an infection ? or it has moved? ive had problens before i gad leep and something eles done but ive been fine ever since im 22