gestational diabetes helpp

So im currently 24 weeks and i went to the doctors today for a infection and they gave me my paper for the gestational diabetes which he said i get done at 28 weeks .

But i am moving before i can even get it done . And i dont see him again for a checkup until the 8th to ask but how soon can you get this test done ? Because theres no way i will have time in the 28 week frame since im moving and going to be really busy.

This is my first baby and i dont want to mess anything up. Has anyone took this test sooner ?