Has anyone tricked you into thinking the gender might be wrong?

I had my ultrasound at 18 weeks and 2 days and the ultrasound tech saw a at three different points of the ultrasound, thus giving her the conclusion its a boy. Well when I told that to my mother she said it could still be a girl and it could just be the umbilical cord between her legs. The thing is the ultrasound tech actually went the extra mile and determined what was umbilical cord and what was baby and she said she could still see a kick stand. Has anyone had stories where they were positive about the , but family made them worry differently?