Contractions or gas pains?

I'm a FTM so I don't know what to expect. I started having what felt like painful menstrual cramps last night. It didn't come and go, it was just consistent. I chalked it up to gas pains because all night last night I had loose BM and after that I would get some relief with the cramping. This morning I still have cramping but can't get any relief. I live an hour and a half away from the hospital so I do want to go as early as possible but only if it's the real thing. What do you ladies think? I'm 39 weeks today.