abnormal uterine bleeding
"I got Mirena in about five months ago. It was very painful when I got it inserted, I have no children. I was bed stricken the whole day proceeding the insertion.  Since then I have felt great. I am pretty sure it has  contributed to a little weight gain and some mood swings but nothing out of control.  My partner can barely feel it. Also, I do not really get my period, which freaks me out a little, but other than a few cramps (and I used to have unbearable cramps) during my period time, I love it."