I drink water all the time too. And have been to labor and delivery 3 times now cause of Braxton Hicks that are painful and like 4-2 mibs apart. Most times it is because we are not drinking enough water for our body mass. Once I picked up my water intake it slowed them, but I would still go into them, like yesterday when I ended up in my doctors office 4 mins apart again. Point it, if your cervix is still thick and not dilating, you aren't close to labor, it is just an over active uterus of pick up your water intake.
If you're that far along, ER should triage you and send you to L&D.
You should be going to labor and delivery triage. Not messing with thr Er. They will tell you weather your actually having contractions.