WOW I am feeling so thirsty today too. I did with both my other pregnancies and was tested both times and didn't have Gestational Diabetes.
Sometimes I feel like....hope people know this scene from 'Look who's talking'....where Kirsty Ally is drinking a whole container of juice in front of the open fridge with the baby inside her tugging on the cord wanting more LOL Gosh I really feel like watching that movie now HAHA

Thanks Yogababy for letting us know its also the increase of blood volume....makes me feel a bit better.