IUD Questions/Concerns

Hey everyone! I got my Kyleena IUD on January 29/17. It was excruciating to get inserted but felt totally fine by the next morning. I still haven't had a period, but I did have a tiny bit of spotting and some period symptoms the day I was supposed to get my period. But yesterday at work I got a really awful cramp that felt deep and made me nauseous and I could feel the strings for the first time. its still cramping a little bit today but I can no longer feel the strings, neither can my boyfriend, and we had sex last night.

I'm going to call my doctor tomorrow, but has anyone had this before? I'm looking for peace of mind.

TIA