Levonorgestrel
"I've had the mirena for about 2 years. Everything's been fine up until last week. It was a little early for my period, but eh, I've never been regular. We were running across the street and I felt something stab me on the inside. I'm pretty sure the mirena has moved (again). Since then, I've bled heavily for a day, then not at all, then I bled for a day, then not at all. It doesn't hurt. There's not even a cramp. It's just blood. I'm going to the doctor to check it out and make sure everything is okay. Just thought maybe someone else went through this."