Only if the pain was "moving" really is it a kidney stone. The stone as it passes the pain actually travels through your body, starts as a lower back burn/irritation, then the stone moves and it is an INTENSE pain, then subsides, then moves, then subsides...until ultimately you piss and it BURNS and hopefully a little stone flows out.

I've passed 3, so the pain is easy to describe and I can usually tell when one is coming...it sucks hardcore