They got the gender wrong

I have a son and was told months ago i was having a girl. I was over joyed and could picture her. I boight lots of pink clothes and packed my hospitsl bag. At my scan yesterdsy it turns out that its actually a boy.

I have to admit that i am devastated. I wouldnt be if i knew from the start but in my mind i had a daughter and now i dont.

Has this happened to anyone else?