Big baby?

Kaelina
At my anatomy scan four weeks ago my OB said my baby was measuring in the 80th percentile which I guess is larger and today at my normal appointment he asked. "So how pregnant do you feel?" And I said I wasn't sure. This is my first pregnancy. And he said "well we have you at 24 weeks today but you are measuring at 26. So that's a big baby" My question is what does this mean? I froze up at my appointment haha and missed out asking questions. Am I 26 weeks pregnant? Is my baby developed to 26 weeks? Or is she developed to 24 and just large? Should I plan on having her sooner than my due date? Just looking for advice. Obviously I can and will ask him when I go in next month.