Finding out gender today :)

Ryan
Have to get a ultrasound today to check out my cervix length to see if I need to get my cervix stitched so I can carry baby full term. The tech said she can tell us the gender since I'm 15 weeks today. How accurate will it be since it's so early? My next ultrasound isn't until 20 weeks. Did know if we should wait to tell baby until then.