What was your fasting glucose level? Having gestational diabetes, if not controlled, can cause a baby to overgrow that could be one of the reasons for induction or cs.
Only for sure way i think is with the glucose test its a controlled amount and they are testing to see how fast your body breaks it down.
I had it with my first pregnancy and I have it this pregnancy too...I had to be induced my first pregnancy bc my son has a heart problem not bc he was too big...
Even if you declined the glucose test, they test your urine at every appt for sugar and protien. Possibly your urine has had consistantly had sugar in it so your dr may be taking a precaution. It is very important to be diagnosed if you do have it. I have it but because im following the diet, mine is under control and not on medication. I know it may suck but its best to either take it in and do what your dr has suggested for your babys sake or talk to him or her about your concerns. At first i was angry with myself when i found out but now i just look at it im much healthier and have hardly gained any weight and im 32 weeks. And 3rd pregnancy and didnt have gd with first 2 pregnancies.
Your fasting numbers is what there main concern is.