Yes it's totally normal. They are your feelings and they are valid. I have 3 girls and always wanted a boy but we are done and it's not going to happen. It was REALLY hard for a good 2 years but I think I am mostly over it. For a while I didn't know if those feelings would ever go away! Then my brother had a boy and some of the feelings came back but they are kind of going away again. It's a tough issue because you feel badly and then feel guilty for the way you feel. It's hard to separate them but you should not feel guilty for feeling a certain way.
These feelings will likely go away at some point. Don't beat yourself up.