Experience with measuring ahead?

Hey y’all! I’m a FTM so this is all new to me! At my appointment today i was measuring 3 weeks ahead. The dr wasn’t concerned and said that now that I’m going every 2 weeks, if I measure bigger in 2 weeks they’ll do an ultrasound to look at baby’s length and weight! I know there’s different factors that can cause this! Just wondering who has experienced this! Did you end up having a big baby?