Bad Cramping pains a week after IUI, ovulation or implantation?

So usually I have pretty bad pains around ovulation which tend to be localized to one side and it also feels like I'm constipated or have gas.

So when I started taking the Clomid for 5 days, I started feeling pressure and slight pain in my ovaries which never really went away since then. I was expecting the pain and pressure to go away a day or two after the IUI since that's when I was supposed to ovulate. It lessened, but didn't go away 100%. But I never felt any actuall ovulation pain like I normally do until today a week After the IUI was already performed.

Is it possible to not respond to the Ovidrel trigger shot and ovulate later, or one egg ovulated and a second egg ovulated days after? I had a mature follicle in each ovary.

Or could it be possible implantation?

Or could it be the corpus luteus?