Failed one hour glucose =/

So I got the dreaded call that I failed my one hour glucose. I even fasted the night before and didn't eat or drink for 12 hours before the test. I don't understand =/ now I have to go for the 3 hour one and I am dreading it! I passed the one hour with my first son...not sure why I failed with this one. Has anyone had any luck passing the 3 hour one and did you do anything different to ensure you passed it? I'm scared about the whole gestational diabetes thing!