About glucose testing

Chelsea

So today I am 29 weeks exactly and did my glucose test. My level was 148 and I guess the normal is 140 and below. I was told to eat but I didn’t before hand could that possibly be why I failed? My Ob is willing to do another 1 hour glucose test instead of the 3 hour. Did this happen to anyone else ? I need advice what to eat the night before and morning of my test