hey, try not to stress about it I had the same issue but left it and it continued to get worse and worse it turned out the IUD marina had punctured my uterus and it can cause severe medical issues in the future if not looked into I don't mean to scare you at all but please ask your wife to have a CT SCAN NOT an ULTRASOUND as it isn't known to show up on an ultrasound.. and it can result in death. I wish use all the best and hope that's not the case but please have it checked in case