Doctor Appointment

I went in at 31 and 2 days I think. The doctor said I was measuring 32 weeks which they’ve never even mentioned a measurement during my entire first pregnancy or this one (until now). With my first (a girl) she kept saying how small I was but I had a long torso so there was no way of telling how big the baby was and said I could be hiding a big baby in there. Well with this one (a boy) maybe my muscles are all stretched out or positioning as he’s hanging out low? I have gained 16#. She’s like let’s keep this baby 8# and under (my first was 8#). I’m thinking how do I do that 🤷🏻‍♀️ I’m not overeating to my knowledge. I’m just worried I’m going to have a big baby! Thanks doc for planting these worries.