Implantation pain or something else??

I’m currently 5dpo, unless my opk was late. This is my first Clomid cycle. Last night around 8:30, I started having really bad pains in my lower abdomen (uterus maybe?). It did not feel like period cramps. It was like a searing pain. I couldn’t stand up straight and had to get in bed. Also if the area between my butt and vagina got pressed on, like by sitting, it felt like a knife shooting into me. I also had Tenderness if I pushed on my lower belly.

All during the night I woke up every couple hours to bad pains. It hurt so bad that I could barely push hard enough to empty my bladder. One time the pain was so severe, I got dizzy and broke out in a cold sweat.

Today I’m still feeling it but not nearly as bad. I can move around and sit fine and it’s more on and off this morning, not constant like last night.

Has anyone else experienced something like this? Could be it implantation? A clomid side effect?