Failed 1hr glucose test after fasting

I was scheduled to take the glucose test at 24 weeks and OB told me to fast at midnight day before the test. I got to the clinic at 10am (late and hungry) and my glucose level still went up to 154. My OB told me to take the 3hr glucose test before our next appointment which is June 23. How likely is it that I am going to fail the 3hr test after the failed 1hr test with fasting?