How much do you have to drink, as in how many ounces?

Are you put on a time limit for drinking it?

What happens if you cant finish the drink in the alotted time?

I'm asking because I take my 1 hr test on the 12th. I was told no food or drinks after the midnight before. I still suffer from morning sickness, especially on an empty stomach so I know I will be miserable. Plus, I'm an extremely slow drinker. If I gulp or chug something, it comes right back up.

I'm a lil nervous.