Having mixed feelings about gender

I have an almost 4 year old daughter and yesterday we found out baby is a boy. I have no idea why this is causing me so much anxiety. I ways saw myself as a "girl" mom (I do have a 7 year old stepson with whom I've had trouble bonding with despite efforts...but I get it, he is very loyal to his mama as he should be. Side note: his mom and I get along great! :)

Has anyone else felt this with finding out the gender? Of course I will love my son endlessly bit I'm still feeling awkward about it. :/