You are not alone!! I have this happen too, actually the other day when marie brought up hearing things in her belly I asked about this same thing.. here is the post..
http://www.medhelp.org/posts/show/443278
I swear it's the same thing that I have going on too, it doesn't hurt at all but it is like a shock, I described it as a current going through my belly. I'm sure it's nothing to worry about, as Brayden hasn't lessened his activities at all since it happened with me.