Can someone explain this to me.

Kat • First time mommy to a sweet little boy due in October ❤️
At 33 weeks my baby was measuring at roughly 35 weeks weighing about 5.5lbs at the doctors office. Yesterday at 34.3 weeks he was measuring close to 37 weeks at 6lbs and 11oz. How is that possible and what does that mean in comparison to his actual due date?