A source revealed the pregnancy news almost one week after Aguilera tweeted on Valentine's Day she had gotten engaged to Matt Rutler, her boyfriend of three years.
Aguilera already has a six-year-old son named Max with ex-husband Jordan Bratman and they share custody. The singer and Bratman wed in November 2005, welcomed Max into the world in January 2008, split in October 2010, and ironically finalized their divorce on Valentine's Day 2011.
Aguilera met Rutler on the set of her 2010 film Burlesque where he worked as a production assistant. The couple has been living together in Aguilera's new Mulholland Estates mansion in Los Angeles, which she bought in April 2013 for $10 million, according to Us.
Aguilera starred on The Voice for its first three seasons before taking a break in Season 4, when she was replaced by Shakira, to spend time with her son and concentrate on her music career. Aguilera returned to serve as a coach for Season 5, but will once again have Shakira fill her shoes for the upcoming sixth edition, which premieres Monday night on NBC.