My body rejected the Mirena as well, but luckly it happened right then and there at the appointment as I was leaving!!! And it does hurt like hell. But I would just get it removed, I know everyone is different but maybe the Mirena is just not right for you. After 9months of having it in, I had to remove it because I wouldn't stop bleeding. I would have 3 week periods and only 2 or 7 days break!! It was stupid. I would rather have a 7 day period than a 3 week one!. Good luck and take care of yourself listen to what your body is telling you, everything happens for a reason.
Sarah