This is going to sound strange.

Do you have a cat? Is it friendly enough to take a nap on her belly?

When I get bad cramps I take my Milo and lay him across my belly and pet him until he purrs. the combined warmth and vibration seems to help.

You know, I bet some sort of vibrating heat pad job would do the same thing!

And, no worries. I was 11 when I got mine.