But according to the Daily Mail, the pregnant star encountered a little bump in the road while getting ready for the event: how to dress her burgeoning belly.
Just one day earlier, the former "Married With Children" actress -- who joked to "Entertainment Tonight" that her due date is between "zero and 10 months" -- took to Twitter to express her frustration over finding just the right outfit for her suddenly fuller figure.
"Who are these women who can wear a short dress while pregnant?" Applegate, 38, tweeted. "Seriously, congrats ladies, cuz it ain't gonna happen over here. Yikes!"
By the next day, Applegate, who announced July 21 that she and fiancé Martyn Lenoble are expecting their first child together, still seemed uncertain about her attire.
"About to get ready for the Cats and Dogs dealio," she Tweeted. "All is well except that I don't know how to dress this belly yet. So big black shirt it is."
She clearly felt good about her decision. Standing on the red carpet at the "Cats & Dogs" event, Applegate, who accessorized with multiple necklaces, bracelets, and a black clutch, glowed as she cradled her tiny tummy.
Credit those sky-high heels with boosting her confidence. Wearing them, she told "Entertainment Tonight," "offsets the impending growth of width."
In related news, Applegate might also be interested in something from Forever 21's Love 21 Maternity Collection.