When to get gender screening?

Tiffany
Okay, so my husband is gone to basic training but will be back right at August 1st (I'll be like 21 wks preg)but will have to get straight to work with football. He is also a coach. I would like to hurry up and get my gender screening done at 16 weeks when I heard it's possible. There's a place that does that all the time, I'm just nervous that it'll be too early and they'll tell me the wrong thing. My OB has me scheduled for an appointment at 18 weeks pregnant and said that I won't be finding out the gender at that appointment. I'd rather fine out sooner because I could get work done in nursery and buy stuff for the baby. But what do yall think I should do?