Braxton hicks or labor??

Okay so I'm 29 weeks and 5 days pregnant. I keep getting these extremely uncomfortable cramping feeling and it's been going on for about the last hour. It feels like painful menstrual cramps and I'm waiting for my doctors office to call me back. I've been drinking water like crazy because I read it could help. Just wondering if other moms have experienced this at about 30 weeks or if I should go to the hospital? Thanks 😊