gender confusion

My colleague told me this news today. Her sis-in-law went to Specialist A to have her tummy scanned & the doc told her it's a boy. Happily, she went to the GH for her routine checkup and scanned the second time & the doc said the same thing, it's a boy.

However, when it was near her due date, she switched to Specialist B and the doc told her that she will be getting a girl. She was so shocked and upset cos she already told the whole world that she will be getting a boy. Addition, the couple already bought all the things to welcome a baby boy. Imagine how devastated she was. Finally, she gave birth to a girl.

I am confident in my doc and there will not be any mistaken identity case.