The former The Hills star announced on her phone app that she's pregnant with another baby, Us Weeklyreported.
After teasing she had big news on Twitter, Cavallari reportedly revealed on her app, "We're at it again! Thrilled to announce baby number 3 is on the way! The cutler crew just keeps on growin'!"
Cavallari and the NFL Chicago Bears quarterback are already parents to Camden, 2, and Jaxon, 12 months.
In the photo Cavallari released, her sons were sitting in a little red wagon and she was standing in front of them while making a heart-shape with her hands on her stomach.
On May 9, Cavallari and Cutler attended a charity gala together during which the mom-to-be gushed about her little ones.
"Camden is a really good big brother," the shoe designer told Us. "He's very protective and very sweet, But he also gets a little upset when Jax tries to take his toys and messes with his stuff. He gets a little territorial with some stuff, so it's kind of funny."
Cavallari had also reportedly said she wants three kids although her hands have been pretty full as is.
Cavallari -- who also competed on Dancing with the Stars' thirteenth season -- and Cutler wed in June 2013 and reportedly honeymooned in Italy. Cutler proposed a total of three times because they had an on-again, off-again relationship for a while.