Gender Disappointment - Wanted A Boy But Expecting A Girl

Went for an ultrascan at 17 weeks and the gynae says the baby is healthy and we may be expecting a girl. I'm more than a little disappointed because I've been dreaming of having a little boy and this is honestly not what I'm expecting. Having growing up with two nieces and two nephews since they were babies, I have an overwhelming preference for boys. And I just can't help feeling disappointed that I'm now carrying a girl. My husband thinks it's silly and I should be glad that the baby is healthy and well. But I'm trying hard to come to terms with it. Somehow still holding on to hope that the baby will turn out to be a boy at the next ultrascan or even at the delivery room. Has anyone experienced gender Disappointment? How did u handle it?