Iud question

So I feel like my body's partially rejecting my iud, I get really sick and crampy and when I'm ovulating I will bleed a bit and just feel miserable. I know it's still in place but I don't know what's going on. I was fine till about three or four months ago. It's also a bit concerning that when I bleed it's like a dark little bit mixed with discharge. 😅 I don't know what to do. Any advice?