I found out at 14 weeks I was having a girl with 3D ultrasound I'm now 38 weeks and it's still a girl :)
I found out I was having a baby boy at 16 weeks pregnant. (: but they say ti wait until 18-20 weeksbbevause then the baby is more developed and it's easier to tell if its 100% boy or girl.
I'm 20 Weeks And I Find Out November 5th
You usually find out between 18-22 weeks (when they do the cartioligy scan). But you can find out at 16 weeks if you pay for an ultrasound privately. But it's not 100% accurate then. I found out at 16 weeks with my now two year old daughter, but the ultrasound tech was only 60% sure, but she was right. :) I'd say it's best to wait until your 18-22 week scan though.