Timing of "20 week" ultrasound?

Hannah
I am 11 weeks today, and just got the full list of appointments from my doctor's office (they schedule everything all at once). Anyway, they don't have the "20 week" ultrasound scheduled until the day before I will be 23 weeks. Is this normal? We are not planning on doing the early genetic testing (when I know a lot of people find out gender), and I just don't know if I can wait until 23 weeks! It seems most of my friends (and sisters) have had theirs at 18-20 weeks, so I'm thinking about calling to see if I can get it moved up a couple weeks unless there's actually a medical reason to wait that long... would love to hear any feedback! Thanks!