Carrie Underwood is going to be a mom again! The singer is expecting her second child with husband Mike Fisher. She announced the exciting news in an Instagram post on Wednesday. "Mike, Isaiah and I are absolutely over the moon and excited to be adding another fish to our pond," she said in the video. "We're just so excited and glad you guys can share this with us and be a part of it. Love you guys!" The couple are already parents to a 3-year-old son named Isaiah. Congrats to the happy pair on their growing family!