I have the IUD since surgery and I have SEVERE periods now. The pain is so bad sometimes that I feel like I'm gonna die. I have also noticed that it's not as comfortable during sex either. It is sometimes actually painful, as if something is hitting the IUD. I think my cervix is probably just very tender, but it's NOT a good feeling sometimes. I don't feel that this is normal. I need to go back for a checkup appointment to see why it feels this way and why I am having this severely painful periods. I was under the impression that they may stop all together or just have two or three a year. Not my case....
But it is nice to not have to worry about pregnancy. Just remember that you will be more fertile now that you are dropping so much weight. This somehow boosts the chances for getting pregnant, so if you don't want a baby, you better do something.