I was diagnosed with GD for my second pregnancy and now I'm haveing similar symptoms with my third. I know it can be agonizing and unfair.
Last time I was guilted by a nutritionist for having 2 glucose tests over 120 (and barely) in a month and told if I didn't do better, I would have to go on insulin! At the time, I was uninformed enough to believe her and felt terrible. I would cry at restaurants, starving and trying to figure out what I could eat.
This time I have armed myself with information. Just like prairieo (and thank you, prairieo, for the research, I hadn't found that book yet!) said, there is a ton of misinformation regarding blood glucose levels during pregnancy. For one thing, the tests are terribly unscientific. Also, no one has ever monitored a "normal" woman's glucose level during pregnancy. To me, it all seems like a giant ploy to make money. Worse, it further underminds a woman's confidence in her body. No one should be shamed for a blood glucose test result!
I've learned about some other things, through observation, about what affects the testing. Stress! When I'm pissed off, my blood sugar jacks up. I can be fasting and test when I'm mad and it wil be high. Exercise is another thing, initially, my blood sugar will dip down when I'm more active, but then after a while it will spike, I think it's compensation. I think my body knows it might need more sugar if I'm working harder.
If I were you, I wouldn't even get the test, I would just monitor sugar levels at home for a while and experiment a little bit. See what spikes your sugar and what doesn't and develop your own eating plan to keep it in check. If you have to get a diagnosis to have access to the monitor, I guess the test won't hurt anything.
Please don't let anyone make you feel bad. You aren't doing anything wrong. Most likely, your body and your baby are perfectly healthy.