Mirena IUD question? need advice?

i had a comeplete miscarrige 3 weeks ago (no d&c) and had my mirena put in at my 2 week check up (last week). i stopped passing clots from the miscarriage a couple days before i had the mirena put in, but right after i got it the blood clots came back. its been a week and im still bleeding (less clots just more bleeding) and having pretty painful cramps. could it finally be my period? or should i call my doctor? my strings are sill in place (i checked). i just know i'm supposed to have a period sometime after my miscarriage i just dont know when? any advice?