Measuring 2-3 ahead?

Brittany

I’m due on Christmas Day with my second little girl. I have been measuring right on track the whole pregnancy up until yesterday. My water broke at 29 weeks with my first baby so I had an ultrasound yesterday to rule out any loss of fluid. I had a routine appointment last week and measured perfect. I’ve gained 20 pounds so far and I’m 31 weeks along. My fluid level was perfect yesterday and my baby was healthy and active. The only thing they mentioned was that she’s measuring ahead and already almost 5 pounds. Some of her measurements were at 35 weeks and some were at 33 and some were at 34. The average of her measurements was putting her a couple days before 34 weeks. She’s head down and already super super low. They said they wanna see me back in November for a growth scan to see how baby is doing. With my first baby she weighed 2.11 at 30 weeks, this baby weighs almost double that at 31 weeks. I had weekly ultrasounds with my first due to being high risk. But this pregnancy has been perfect until now. How is it possible that my stomach measures right on track but the baby measures weeks ahead via ultrasound? Anyone have any advice or any experience with this? Did you deliver early?