Can't believe I get to respond to this question (just found out GIRL yesterday).
With my boys, all of them I had some boob pain, starting around 9w.
With this one, I feel like my milk has come in and I am really engorged (started around 11w).
My friend had 3 girls then a boy.
She had NO pain with her girls, and painful boobs with her boy. I guess it just depends. Hope you get your boy!