Patience in pregnancy...

I had a doctor appointment last Monday- everything looks good.  Heart rate of the baby was 150. I was hoping to make an appointment within the next 2 weeks for an ultrasound and to find out the boy or girl status.  However, my doctor is conservative and is making me wait until 20 weeks (even though I tried to sneak in an earlier appointment...).  So the big date is Friday Feb. 27th- which is later than 20 weeks (so requiring more patience on my part.)