Nick Lachey and Vanessa Minnillo on September 6, 2012. Credit: KM Press Group

Now that summer has come and gone, Nick Lachey and Vanessa Minnillo's baby countdown is kicking into high gear.

Due sometime this fall, the expectant mom-to-be stepped out in Calabasas, Calif. Thursday with her husband, where they strolled hand-in-hand on the way to a lunch date.

Vanessa's baby bump looked bigger than ever underneath her purple knit maxi dress, which the Wipeout host, 31, accessorized with a denim jacket, silver hoop earrings and oversized sunglasses.

In July, Nick opened up to Us Weekly about getting ready for the arrival of his and Vanessa's first child together.

"The nursery's ready, we got the stroller, we got the car seat. Now it's just emotionally figuring out what we do, and I don't think that ever ends," the 98 Degrees member shared. "I've assembled a couple strollers at this point, and I'm pretty confident. If my brother [Drew Lachey, 36] can handle putting in a car seat, I feel like I have a pretty good chance. If he can do it, anyone can do it!" (Drew Lachey has two kids with wife Lea Dellecave).

A lot has changed for the couple in the past year, Lachey acknowledged. "You get married, you get pregnant, and it all kind of happened so fast," he told Us. "But it's very exciting!"