My niece did one of these tests, girl positive.
She did the Drano test, girl positive
She did the heartrate test, girl positive.
She did the Chinese birthday test, girl positive.
Today she had her 20 week ultrasound.
She is having a boy.
I wanted another girl, after our first one. I did not want to know the sex before birth, though.
The sweetest surprise of my life was finding out upon delivery that it was just as possible to fall head over heals in love with my little boy as it was with my girl.
People who want every detail nailed down leave so little room to be surprised and delighted when life throws you a happy curve ball.