Measuring a head?

UPDATE::::: had our ultrasound today our little man is measuring 2 weeks head. And weighs 5lbs and 12 oz. My lmp was may 15th that would make my due date feb 19th. But my doctor switched it to march 1st when i was 8 weeks which put me at 6 weeks... would make loads of sense now. As i am measuring 2 weeks ahead of my march due date.... lol which one would you go by?? Feb. Or march.

So ive known for a while i have G.D and i have changed my diet no carbs fresh veggies and fruit, nuts & salads. Granted i was a little overweight before this pregnancy... ive only gained a total of 14 lbs so far. I am 32 weeks and 1 day. Due march 1st. And today i was told i am measuring at a whopping 5 weeks ahead! Baby is head down. They did a NST and we did good. I have an ultrasound scheduled for the 10th to see more accurately how big my little boy is... any one else measuring ahead???