I couldn't wait, so I went to a 3D/4D ultrasound place, I paid $40 and I'm having a boy! If you have the money go on Yelp to find a good ultrasound place. Btw I'm 16 weeks pregnant too and you can see perfectly that its a boy.
My doctor was trying to make me wait that long too so I went and found somewhere that does nothing but ultrasounds and got a 3D one done. I found out at 20 weeks.