Gestational diabetes

So I went for the 1 hour glucose test last week. I got a call back saying my glucose number was a little high so I have to go back for the 3 hour test. Anyone experienced the 3 hour before? They said they like the number to be 139 or below and mine was 145. :( I am so devastated that I could possibly have it. I thought I was fine because I haven't been swollen at all, am measuring right on schedule and have gained the recommended amount for being 28 weeks. Advice?