failed my glucose test

So I went for my glucose test yesterday, got a call from my doctor a couple hours later telling me he wanted to see me today, I go in today to my doctors and he asks about my family history is diabetes, (which I do have a family history of gestational diabetes) he then tells me it looks like I have gestational diabetes after looking at my results from yesterday, and I have a appointment with my obgyn sometime this week, but I'm wondering why didn't he send me for the 3 hour one? I did the one hour test but he didn't send me for the 3 hour one? He just told me I have gestational diabetes. Did that happen to anyone else?