Ive had the MIRENA for just about a month now, and since maybe about week after insertion, I've been experiencing crazy mood swings. It's never been like this before, so I'm positive it's caused by the IUD. It's tolerable but annoying. My boyfriend deals with it really well, and I totally appreciate him for loving me & caring for me regardless. I'd have to say out of the cramps, the spotting and the mood swings.. Mood swings are worse because I just don't know how to deal with being so up and down.