New IUD

So I got the Mirena IUD last week. I experienced the usual cramping after but it's been a week and I still feel some INTENSE pressure on my cervix. I know It takes a while for your body to get used to it, but this is literally awful. I have felt for the strings and they are present. The pain is sometimes sharp, but mostly a really bad pressure ALL over my pevic region. Sitting down kills. I have to lay, or stand. I've also had diarrhea and constipation on and off since I got it. I been feeling really nauseous too. like I've almost thrown up a few times. Is this normal? or has anyone else had this before? I have my IUD check up in 2 days and I'm going to talk to my gyno about it, but I wanted to hear from some other women.