For the past 3 years now I've noticed something weird in my lower abdomen, just under my belly button but to the left of it. Everytime I do abs, in certain exercises I get this weird lockup/cramping, I need to stop and massage the area, other abs exercises I'm fine but if I happen to bend over to do something after doing the exercises I lockup\cramp again, it's scary weird, not sure what it could be. I don't get it on anything else but when I do abs.... what could be causing this?