UNDATED (AP) - Now Kelly Clarkson knows why she's been throwing up so much. Clarkson has found out she's pregnant with a girl. Clarkson tweets "only a girl could cause this much drama with all this vomiting." Clarkson has this advice for other pregnant women with morning sickness. She tweets that they should try eating a baked potato. She says it's the one thing she's been able to keep down.