After eonline.com initially reported the pregnancy, Cavallari confirmed the news on Twitter and Instagram.
Cutler, 30 and Cavallari, 26, already have one son, 14-month-old Camden.
“We know we want another one close in age to Camden and we’re at the point where we’re both ready,” Cavallari told E! News in September. “Before Camden was born, I thought I’d be pregnant again by the time he was six months, but I definitely wasn’t ready. Now, I’m finally ready.”
The couple wed in Nashville in June.
It’s still unclear how many children the couple would like to have.
The Chicago Tribune contributed to this report.