Feeling a little sad

Although I am grateful for a healthy baby, we found out Tuesday that this baby is out third little boy. 
To be 100% honest, I didn't care weather we had another boy or a little girl, but when the doctor told us, we found ourselves a little disappointed. This is our last, and was our last chance to have a daughter in our lives. 
Like I said, I AM grateful for this baby, no nayter the gender, and I know my love for this baby will be the same as it would had it been a girl, but I can't shake this feeling of sadnesses. It's more like mourning the loss of a daughter we will never have, than it is being sad it's a boy. If that makes sense.. Not to mention EVERY ONE in or families wanted a girl so badly, I feel like I let everyone down and that people will feel so disappointed, even if just for a minute. 
Can anyone relate or am I just a total asshole?