Sorry this is gonna be a little long

April 1st I delivered a still born, I made the decision to get on birth control. I got the mirena that was May 17th. June was my last period as I expected to happen. Didn't think anything of it. Well yesterday me and my SO had sex and when I was cleaning myself up I got this clot looking thing on the toilet paper except it wasn't normal to me. I've never had that before. I usually have pretty horrible periods and get blood clots but this had no color. I started spotting later on yesterday and then today I am bleeding more heavily and have wicked cramps. Is it possible I'm miscarrying? Is this normal or should I call my doctor? I'm lost as I've never been through this before