Weirdness

After bd last night, I felt a cramp. It didn't last long and wasn't very painful, just there. It was weird. And then of course- tons of different things are running through my head. I'm still like 4 or 5 days away from AF being due. (So I guess it was just "d" not "bd" haha. We are past that window). Why do our bodies do weird things? And make me go crazy wondering what is happening!