Emma, who was today confirmed as the host of Channel 5's Big Brother spinoff Big Brother's Bit on the Side, confirmed her pregnancy to the Daily Mail.
"It's a great surprise, and we are thrilled," she said, later adding on her official Twitter: "@mattjwillis and I are peeing our pants with excitement!"
Emma and Matt married in July 2008 after three years of dating. The couple already have a 2-year-old daughter named Isabelle.
Emma's Big Brother return was announced along with former housemate Brian Dowling's appointment as host of the main show.
"I'm so happy that Big Brother is back on our screens!" she said. "I'm such a massive fan of the show so I'm over the moon that I've been asked to be a part of it. I can't wait to get stuck in."
Emma and the former Busted star quit their hosting roles on I'm A Celebrity... Get Me Out Of Here Now! following the birth of their first child.