7.8 score for glucose test

RR

I did my test about a month ago and my family doctor didn't call me back to retest so I assumed I passed. I saw my ob today and he said to pass you have to score 7.8 and below and since I got right at 7.8 he wants me to do the 2 hour test. Should I be worried. Not going to lie I loooove my sweets, even before pregnancy. I'm going to do my retest next week. Is really changing my diet from now til then going to make a difference?