The The Voice judge covered her barely there baby bump in a loose white top and a grey cardigan.
News of Aguilera's pregnancy comes weeks after the Burlesque actress revealed she and boyfriend Matt Rutler where engaged.
The child would be Aguilera's second as she already has a 6-year-old son, Max, with her ex-husband Jordan Bratman. The two split in 2011.
The Grammy-winning singer has not yet confirmed the news about baby number two.
2014: The Year in Music [PHOTOS]