BEST wishes to Julie Chen and CBS chief Les Moonves. Chen is pregnant with the couple’s first child. Moonves, 59, who married Chen, 37, four years ago, has three grown children from his first marriage. Chen, who’s due to give birth in October, will have to take maternity leave from “The Early Show” and “Big Brother,” whose fans have been speculating for more than two years about whether she was expecting or not. Well, now she is.