IUD and Scared of Pregnancy

I’ve had the Paraguard for 11 months now. I’ve had sex on it but always used a condom before, but now I am in a relationship and we’re in the horny stage of dating (sex all the time!). He’s probably finished 3-4 times inside of me, and I can’t help but feel so nervous about pregnancy even though I have the IUD. Does anyone else relate to this? Should I ask him to pull out or use a condom instead? It might also be my brain messing with me but I’ve read several comments on here about pregnancies with the IUD. I thought it was 99% effective!?