Metformin takers TMI

So I know metformin upsets your stomach. I've been on it at 500mg for a week and I've actually been decently okay bc I've been watching what I eat. But randomly today I had an episode and it literally was like I was peeing.... but I wasn't. When I stood up it was neon yellow like it was all pee, but I know I wasn't peeing. Has anyone had this? Or should I call my doctor?