S.,
I know I'm measuring "big" with our son due in 6 weeks. On one of my recent appointments, the doctor looked at me and just said, "Yea. There's a big baby in there." I was like, "Huh?" and he goes, "I'm sorry, but this isn't going to be a little baby." I'm 100% fine with that, but at the NEXT appointment I asked him exactly what he meant by that. He told me that he thought my 1st son (8 lbs 10 oz) was a big baby and that this one will be at least that. I've had another appointment since then and nothing was mentioned. Just that my "growth was good". Apparently, 2nd babies are usually larger than 1st born and boys are larger than girls.
Our family has a history of large babies...my maternal grandmother never delivered a baby under 9 pounds and most were closer to 10. My Mom had 4 kids and I was the smallest at 8 lbs 6 oz. My brother was the biggest at 11 lbs 10 oz (delivered vaginally) and my youngest sister was taken 2 weeks early (due to the size of my brother)- she was 9 lbs 3 oz.
In my opinion and in my case, I have a lot of confidence in my doctors and figure whatever is meant to be will be. I teased my mom that I wanted to beat her record of 11-10 and my husband said I'm nuts, lol.
As long as the doctors aren't freaking out (an ultrasound isn't a bad idea) and your glucose/diabetes is fine. Don't worry about it. I think there are other factors that can come into play with regard to "measurements".
Good luck and congrats on the new little one to come.
T.