Can a vaginal scan pick up the sex of baby at 13 weeks?

Not usually: The gender of the baby is usually much easier to see at about 18-20 weeks along. There have been some instances where it can be seen sooner, but usually at the time of your full anatomy scan between 18 and 21 weeks the gender can be seen. Sometimes the baby's position and other factors keep us from seeing the gender even when this far along.