3 Hour Glucose Test and water

SeaBreeze11

I failed the 1 hour by 5 points so, I'm onto the 3 hour one on Wed.  Could you drink water during the 3 hour test?  I was told to fast and no drinking includig water after midnight.  I am still waiting to hear back if I can.  I plan on going in at 6:30 am.  I can't see how it's expected not to drink any water for at least 9 hours.  Thanks!