Does anybody else here have the copper iud? Do you think it's reliable?

TMI but.. I recently had sex with my SO and he came in me. At first I was okay with it and let him, but a few hours after my pelvis hurts then my whole body hurts. I don't know if I'm just being paranoid. I've had my IUD for 4 years and have had no problems with it. Although i barely bleed when i have my period. Now i'm just worried that i won't really know if i get pregnant or not.

P.S. I do want a baby. But not this year 😑 i'm not ready for it yet