How early do mummies do the gestational diabetes test?

Mine was scheduled at week 24, I was kinda sad my "freedom" days are gone soon as I think I have high chance of having GD because my immediate fam has it and I can feel low blood glucose after a meal before preg (that makes me worry my insulin is not working well) I don't eat much sweet stuff, just once in a blue moon, but I do enjoy the freedom to eat without diabetes like strict diet... #pregnancy #GestationalDiabetes#advicepls