Well he isn’t having the kid in particular but his new wife Brooke Mueller is; Charlie managed to knock her up too.  Man-whore Sheen states:

“Brooke and I are thrilled! She’s the best stepmom Sam, Lola and Cassandra could ever hope for. Seeing her love and affection with those three, I know she’ll be an amazing mom. Unless I bat 100 percent, perhaps a boy awaits us.”

This is his third relationship with children, this man gets around; poor bastard children.