Protect your child from these ideas OP.
Gender disappointment is a thing, and should be acknowledged but it should also be explored and challenged, because the genitals a person is born with don't make them who they are.
I have three children, all them.
I didn't have a preference in sex with DC1 and we had a beautiful DS. He became very poorly and died when he was still a young baby.
Pregnant with DC2 and I hoped we'd have another boy because I wanted the chance to raise a little boy like we should have been doing. We had our wonderful DD and I was a bit disappointed for about a moment but I soon realised that it didn't matter. She was her own person, a second son also would have been his own person. It has been a privilege raising DD.
When I was pregnant with DC3 I once again didn't mind either way, someone expressed to me they hoped we had another son to make up for not having DS1 here but I knew it didn't matter because another son wouldn't be DS1, he was irreplaceable. This baby would be whoever they were. As it was, we did have another son and I love him to bits because he is him, not because he's another boy. Once again it is an absolute privilege being his mother.
All three of my children are uniquely them and so different to each other, and all absolutely wonderful. My girl has some typically "girly" traits and interests and some more "boyish" ones- because she's a unique individual. DS1 was a calm, easy going baby and so is DS2, I don't think this is because they're both boys but just chance of genetics (DD is a bit of a live wire!) Both DS's are also quite different to each other too, despite both being calm they have a different energy.
And for those trotting out gendered stereotypes, so much of it is learned because we live in such a heavily gendered society.
Best of luck with the rest of your pregnancy and birth OP, your baby will be absolutely wonderful whoever they are.