As far as I knew the 3 day carb diet and 12 hour fast was only if you have to have the 2 hour glucose test(if you fail the first test). Ionly had to do it with the 2 hour test anyway.
Yep - the fasting test is only done if there are concerning results from the first test where you have the yucky drink.

My Dad has type 2 diabetes and my sister had GD so I've had an early screening one. The drink is yuck but not like medicine. I really wanted to brush my teeth afterwards!