Does anybody else get anus cramps?!

I used to think I was alone in this, but I recently saw on an instagram post that some women do experience this. For me it happens between periods during my fertile window. It lasts about a day and my stomach also cramps. I thought it had to do with maybe me being able to feel myself ovulate but I don’t know. It’s so weird. I could be walking in the store and all of a sudden my anus cramps and I have to suck it in lol 😂. I have been experiencing this for as long as I can remember. Can anybody else relate?