Its prolly pretty accurate.. If i were yu id get it confirmed before buyin stuff tho..
They told me at 16w2d mine was a girl nd i really dnt see how it could be mistaken but im havin it confirmed tuesday nd ill be 20w3d
She thinks? I'd be wanting a little more assurance than that, haha! Mine was 18 weeks too, and my U/S tech said it's a girl, then moved it around and said oh yeah that's definitely a girl, and she said she'd tell you don't buy all pink if she wasn't sure, and she told me she'd buy all pink in my case. If she looked and actually saw a labia, and explained it to you, I'd say it's pretty accurate.