How much water do you drink?

33w4d- I've never been much of a water drinker (I know, I know). This past weekend I was out all day, on my feet, it was rainy and cold so I wasn't thinking of making sure to keep hydrated. Monday rolls around and I end up with a stomach bug and couldn't keep ANYTHING down.. I ended up having contractions 5 minutes apart, having to go to the ER and they told me I was EXTREMELY dehydrated and needed 3 bags of IV fluid.. Afterwards when they released me they said I should be drinking a gallon of water a day.. A gallon.. I can barely drink 3 regular sized water bottles per day. Any tricks you guys have to keeping hydrated throughout the day??