Levonorgestrel
"I have to say.. After reading reviews I was a little terrified to get Mirena inserted. However, my ob is really good and it wasn't a big deal at all! It was uncomfortable like a pap but it was done within a few mins.  I gave birth 8 weeks ago and he said this was a good time to get it inserted because my cervix is still soft. So maybe that's why it was no big deal for me? So far, no cramping, slight spotting. I'm not sure about the long term effects of the mirena because I've only had it in a week. So far, so good!"