I was going to do exactly what you were going to do. I had a appointment on Friday (i was 15wks 3days). we wanted to use the baby's 3d/4d ultrasound picture on Christmas cards and that's how we would let our close family and friends know the gender. But my baby was really camera shy. It took forever for him to open the legs to find out whether it was a he or she. And the lady had to have us reschedule the 3d/4d for when I'm 20weeks for a better view because his facial features aren't that great. More skeletal looking. LOL That had shot our plans for the Christmas cards.
I was told it does look like a baby at that point