I had the Mirana for 4 years and had to get it removed for the same reasons. I had a normal flow for the first 3 years then all of a sudden my period stopped. I did experience a swollen stomach and sharp pains. And especially the bleeding after sex, which all started after 3 years. I did take a pregnancy test as you did thinking that I could have been. I actually got a positive. I went to the doctor and they did a blood test, that came back negative. But around 3 1/2 years I started putting on excessive weight (3-5 pounds a week). This had the doctors stumped. I didn't want to remove my iud since it seemed to be the only birth control that had worked for me. However around the time that the 4 year mark rolled around I was advised that it needed to come out since I was having major issues and if I didn't remove it then I could cause more damage to my insides. I have had mine out now for a little over a year. I am on a second form of Birth control and I still haven't had a normal period. I believed in them however the effects I am still having I wouldn't recommend it to anyone. If they can find another form of Birth Control that works for them then go with that one. I only went with the Iud since I had tried both the pill and the depo shot and had major bleed though with both of them. I hope you do not have the same issues as I did and that you can have a normal life since it is removed. I wish you well!