Yesterday I had sex with my boyfriend and it hurt a little when he was going fast (like a pull in my uterus) later on when I used the bathroom I saw light pink discharge and today I had some cramping. I've had my IUD for almost a year and I've notice that this is something that happens after sex. I've been meaning to go to the doctor but due to a terrible experience I haven't gone bad. The last they told me was that I have a cyst.. Could it be that? Or the IUD that's hurting me?