IUD stuck?

I have the copper IUD, I’ve only had it for around 5 months, but I have a lot of cramping and bleeding. With my last period, I was bleeding through a tampon and pad every half hour for 2 days, then 2 hours for 3 days.

I went to get it removed yesterday, and they couldn’t get it out. They actually pulled the strings out with no IUD attached to it. And couldn’t see where the IUD is. With the ultrasound they could see it was still in my uterus, but couldn’t see it to pull out.

Has anyone experienced anything similar? I’m not sure what happens next, I’m waiting for a phone call from them within the next few weeks

I’m worried about it potentially travelling somewhere else, or ending up pregnant, or needing surgery. Since yesterday, I’ve been having so much more cramping too.