Are sugar crashes a sign of gestational diabetes?

I don't have my sugar test until may 19th so I have no idea if I have it or not.

But for the past two or three weeks whenever I eat breakfast I end up feeling really weak and light headed. And I feel incredibly tired and like I can't even walk any farther. It also makes me feel shaky, but I have benign tremors so that could be normal for me! Haha

I haven't read that being a sign of GD. but it's got me worried! Or it could be perfectly normal for all I know, this baby likes to make me feel like crap. Haha :)