That happened to me with my 1st. A bit earlier though. It was my Dr who told me he could tell us the gender at 14.5 weeks. He told us boy. Luckily at our next appointment(19.5 weeks) he did another ultrasound. he didnt even check the gender really, but during it he kept saying "she". I said its a boy though. So he checked and said No, its a girl. I was pretty upset for about a week, not sure how my husband felt but I think he got over it faster than me. After a week I got super excited, but needed time to kind of "grieve" my son, that actually never existed