Glucose test questions

I have my glucose test in 2 weeks to make sure I don’t have gestational diabetes and I have a couple questions.

1. I’ve noticed that when I drink sugary sodas (coke, Mountain Dew, even sprite) I feel bad- kind of sick to my stomach and just a general “yuck” feeling. I drink a Coke Zero every day and frequently ginger ale zero also and the zero sugar drinks don’t make me feel bad. Is this a sign that I might have gestational diabetes?? Like my body isn’t dealing with the sugar like it should. I seem to be able to eat sugary things without much issue.

2. Any advice on what I can do after I drink the sugary beverage at the clinic so I don’t feel like garbage all day? Once I put it together I obviously stopped drinking sugary beverage at home but this one is going to be inevitable.