Doctor says I'm HUGE!

So I went to my appt today and the doctor was surprised at how big I was and scheduled me for a measurement scan on Wednesday. She said I look further along so I'm hoping that's the case and not just that mommy and baby are I've thought that I could be further along because I got my first BFP on July 17th on a digital pregnancy test which would have only been 2 weeks 5 days preggo but when I had my first dating scan I measured less than my calculations. Idk I guess we'll find out. Anyone going through this? It could totally just be because it's my 4th pregnancy.