None of mine were wrong, all right in the 5 out of 7 that we found out with . Mind you with 3 of them i got scanned every appointment and my OB is a high risk OB and a specialist scan technician so i would not expect her to get it wrong when shes scanning me every week of two lol. I did question her a couple of times and she was very confident in telling me she was definitely not wrong on the sex lol (i had dreams you see, that they came out the opposite sex so i had to ask lol)