Cramps or "The Bends" ?

I'm a rather new swimmer (1 1/2 months) and the other day I had a bad experience when I got out of the pool. The second I jumped out, I got the worst cramp ever! And it wasn't exactly in my stomache, more in my pelvic area. But I couldn't stand straight upright for 3 hours, I could only sit in a chair bending over grabbing my legs for leverage. I finally just took a hot bath and it went away, but I've never felt anything like it before. Just trying to stand in an upright position hurt so bad and I'd almost involuntarily bend back over. Just curious what this is and how to avoid it. I've heard of the bends, but maybe that has to do with divers ???