I got the Mirena IUD about 3 months ago. I was on the pill for 5 years and then had a couple years of just using condoms/withdrawal before getting the IUD. It's been a mixed bag.

Cons: I have always had awful (debilitating) menstrual cramps and the IUD hasn't made them any better, nor has it eased other menstrual syndromes like bloating, nausea, and fatigue. I also randomly get cramps now throughout the month. My periods are more irregular now and consist of 2-3 heavy days followed by 4-5 days of moderate spotting, which is about the same as before. BUT, I now get light spotting before and after my period, so I end up with 2-3 weeks out of the month that I am bleeding, plus random cramps. The worst part is that I have started to have issues with yeast infections, which I think is due to bleeding so frequently (changes the pH of the vagina according to my doc) and using pantyliners most days. I also had BV (bacterial vaginosis) which I never had before getting the IUD, but I don't know if the IUD was the cause or not.

Pros: I don't have to worry about it for another 5 years -- just get it and forget it. I like it better than the pill because I was never good at remembering to take the pill, I often lived abroad long-term and it was inconvenient to get it, and I feel like it affected my moods.

Overall, am I glad I got it? It's only been 3 months and my doc said it can take 8 months to even out and for cramps and bleeding to subside. So, I'm going to give it a year and see what happens. I really like the convenience of it and that it's so effective. All of my friends who have them love theirs. On the other hand, the yeast infections and BV have sucked and I haven't had sex for over a month because of that. Getting mine put in was pretty awful TBH, it was quite painful and I had bad cramps for about a day and a half, but I felt like it was worth it since it lasts 5 years.