Gestational diabetes

27w5d FTM and I’m going for my Glucose test next week at 28weeks. I’m already high risk due to my age and at 13 weeks I had the test and it was 137 and the norm is between 65-140 so although it was within normal range it was borderline. My baby is also measuring big as she was 2lbs 1ounce at my 25 week appt. all my urine tests have been normal though. I know it’s not the end of the world to get this I just obviously would prefer not to. Anyone who had an early test and was on the borderline of abnormal still have a normal one at 28 weeks? I also don’t get why some places make you wait so long for the test. I heard it can be between 24-28 weeks but they wouldn’t let me go any earlier. :( if I have it right now and have had it for a few weeks I would have liked to know. I’m trying to avoid sweets now as much as I can as I ate them during my pregnancy in the beginning. I don’t know how much that’ll make a difference though. :(