20 week ultrasound

I had my 20 week ultrasound yesterday and the baby is doing great but the tech couldn't tell is we are having a girl of boy. The baby was moving a lot but she was able to get all the images she needed. We know that is what matters, happy and healthy baby. We really wanted to know what we are having though. I hope everyone else that is hoping to find out has better luck than me.  We are thinking of now getting a 3D ultrasound done to confirm the gender.