What Are The Side Effects Of Mirena Intrauterine System?

HI, I am 31 yr old lady with 90 pound wt.My height is 5.3 inches.I have inserted Mirena 6 months ago and I am still bleeding continuously.I have tried Mirena earlier and it took almost 9 months for my body to adjust but after couple of months it got misplaced so we removed it.For those 9 months I didnt have very heavy periods like this time.My query is can Mirena cause cervical cancer? My doc has recommended to do Pap test but for that bleeding should stop which is not happening.What should I do? Please help.