29 Weeks Pregnant - is my baby too big to be born vaginally?

When I had my morphology ultrasound around 21 weeks, the sonographer commented that baby was measuring in the 96th percentile, and that my provider would probably want to schedule growth scans during third trimester to make sure baby wasn't getting too big. I just smiled and thanked her, but I knew that we would not be planning any growth scans based purely on this comment...