Mirena IUD.

Is this birth-control something I can count on? I’ve had it over a year I believe. Me and my husband usually have sex almost twice a day. Sometimes I can be in the worst pain or sometimes it’s nothing. But I can’t feel my strings anymore, I used to be able too and I’ve had super bad pains on my right side. I’ve never had problems with it until recently, also me and my hubby use the pull out method but one day he came in me and that’s when I checked for my iud but I couldn’t feel it? But when me and my hubby have sex I can and it hurts.. should I see a doc? Because I don’t have health insurance right now..