Rumors are flying that Nicole Richie is pregnant, and Page Six has already set it stone.  Now, the New York Post gossip section is reporting that Richie is engaged to her baby daddy Joel Madden.

NOW that she's pregnant, Nicole Richie is getting hitched, too. The tiny "Simple Life" star and her boyfriend, Joel Madden, showed up for the YSL Pool Party to benefit Center Dance Arts at the Beverly Hills Hotel on Thursday night - and she was conspicuously wearing a huge diamond engagement ring. "It was one big rock surrounded by more diamonds," our source said. Richie refused to talk about the ring. Meanwhile, Madden was "overly attentive to her - keeping his arm around her all night - and repeatedly asked her if she was OK." The cozy couple ate everything on their plates, lobster salad and lamb, but refused all alcohol, which our snarky spy called "a first for her."

Maybe Nicole really is pregnant.  She has never really been one to turn down liquor!