U.S. pop star Kelly Clarkson announced via Twitter she and her new husband, music manager Brandon Blackstock, are expecting their first child. "I'm pregnant!!!" Clarkson, 31, tweeted Tuesday. "Brandon and I are so excited! Best early Christmas present ever." She did not mention the baby's gender or anticipated due date in her Twitter message. UsMagazine.com said Blackstock has a daughter Savannah, 11, and son Seth, 7, from a previous relationship. Clarkson and Blackstock were married last month at Blackberry Farms in Tennessee.