False ultrasound?

Dani
I found out I was having a girl at 15 weeks I'm now 17 weeks and 4 days and I've had my doctors and many people tell me to not trust an ultrasound gender reveal at 15 weeks. The tec. Said it was a girl and she pointed at the "vagina" after 30 minutes of trying to figure it out...has anyone ever been told you were definitely having a certain gender by the ultrasound tec. And then come to find out its the other sex? my doctor told me to she had to babies and each time she did the 15 week gender reveal they told her she'd have a girl but they both came out boys...?