The model and TV personality stars as Legend's love interest in the promo for "Wild", which debuted on YouTube on Thursday afternoon (13Aug20), and towards the end of the video, director Nabil zooms in on a shot of the couple looking out towards the water off the coast of Punta Mita, Mexico.
The clip features Legend hugging his wife from behind as she cradles her growing belly.
The stars have yet to directly comment on the apparent baby news, but after its premiere, Teigen retweeted a post on the Vevo account, which read, "@johnlegend and @chrissyteigen drive us 'Wild' in the heartfelt visuals for John's latest song with @garyclarkjr! Be sure to watch it now for a beautiful surprise!"
She also posted a smiling heart emoji, indicating the pregnancy news is true.
The couple, which wed in 2013, already shares daughter Luna, four, and son Miles, two.
Teigen has previously been open about her fertility struggles and their efforts to conceive via in vitro fertilisation.