Hi - i have often complained to my TTC friends that i get bad cramps a day or so after O'ing until i get AF... i really dont know why and of course we are two different people but i just found out i have severe Endo so maybe that was/is the cause of my pain... (i dont want to freak you out.... just telling u what happened with me)
If you're worried about it i would definitely get it checked out

Best of luck
xox