Lacey Chabert is pregnant.

Lacey Chabert

Lacey Chabert

The 'Mean Girls' actress announced she and her husband Dave Nehdar, whom she married in 2013, are expecting their first child together with the help of her dog over the weekend.

The brunette beauty uploaded a photograph of her pet pooch Kitty - who she calls her "first child" - wearing a white pint-sized T-shirt emblazoned with the words, 'My mom is having a baby & all I get is this silly shirt (sic)", across the back.

She captioned the hilarious shot, which sees the adorable Chihuahua frowning at the camera: "Kitty doesn't seem as excited about this as we are ... I'm pregnant!!!! My husband and I are thrilled & so thankful. (sic)"

The news the pair are expecting a little bundle of joy will no doubt come as a surprise to fans as just three weeks ago Lacey showed no signs of a baby bump when she made an appearance on 'Bachelor Live' in a faux snakeskin frock.

However, the couple are known for keeping their private lives close to their chests as they managed to tie the knot three years ago in Los Angeles without anybody - except their friends and family - knowing about the nuptials.

Kaley Cuoco, Amy Davidson and Ali Fedotowsky were among those who watched them exchange vows in 2013.