I found out I was having a little boy at my 12 week scan, they said his 'dangaly thing' it was very noticeable between his legs but she said will definitely find out more on 20 week scan and again they said I was having a boy so the first scan was correct now I can't wait to meet him in 40 days :D good luck
I did at my NT scan at 12 weekz. There were characteristics of a girl anx she was 75% sure. It was reassured at my 3d ultra sound indeed a girl! Like i said there are characteristics that they can tell aT 12 weeks