I was on the pill as well and I never had symptoms like this. I got preg. Two years ago and I was having the same symptoms as I am now. I had a miscarriage then. If I am pregnant do you think it'll affect the baby and it will turn into a miscarriage as well???
I don't know a ton about mirena but I know with the pill you get pregnancy symptoms which are the same as pms symptoms when you first start it. I don't think its anything to be concerned about. Google "symptoms with mirena" and see what other people have said. Or you could call your doctor.