Gender Ultrasound

Hi ladies. 
Just wondering when would be the best time to find out the gender of the baby. I'm 14 weeks and we want to pay to find out the gender. We really want to know, if not we won't find out till January 6 and we fill that so long from now. So my question is when would be the best time for me to get an ultrasound to find out the gender ? Is 14 weeks too soon ?