T.D.
I got the Mirena last December. Let me just say I asked tons of questions about it before hand, yet I was totally unprepared for the pain it caused me during insertion. It was bad. Most ladies will tell you it was mild cramping, but for me the pain was so bad it caused me to almost pass out, and then I threw up! The rest of the day I had bad cramping in my back, uterus, and legs. I bled lightly for about 2 weeks. In my opinion, though, it was worth it. My period used to be so heavy I would have to go to bed with an overnight tampon, overnight pad, and then an old pair of my husband's boxer shorts because I bled so bad for over a week. Now I can get away with just a pantyliner for about 3 or 4 days. I also love the fact that I don't have to worry about taking a pill.
I didn't want to scare you, I just wish someone would have told me that not every woman just feels "slight cramping" when they are getting it put in. But, like I said before, I think it was worth it.