The former American Idol winner, 27, made the big announcement during a charity concert Sunday in Jacksonville, Fla.
"You are the first [people] that I share this news with," she told the audience gathered at the opening of the Riverview Apartments complex. (Watch her full announcement below.)
"And I share this with you because I can relate to you. And for a while, I walked around figuring out what they will say and what will they think about me. But now I tell you, I don't live my life for folk."