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Nick Lachey just announced he’s coming out with his fourth album and is currently working on two TV shows — all while trying to juggle being “the best husband and father you can be,” he tells PEOPLE.

But it’s wife Vanessa — and how she’s handling their little girl on the way — that has left him in awe.

“Vanessa is doing great,” he says. “It’s not easy to be pregnant and take care of a 2-year-old at the same time, but she makes it look effortless.”

As for son Camden John, who just celebrated his second birthday, he’s still adjusting to the idea of a sibling.

“I’m not sure that Camden totally understands the concept just yet, but he does know that Baby Sister is living in Mama’s belly!” says Lachey.

But for the soon-to-be family of four, “It’s very exciting,” he says. “We’re obviously thrilled with our little boy and he’s been an incredible blessing, but we’re thrilled to expand on our family.”

Lachey, 40, will return for a new season of Big Morning Buzz Live on Sept. 29 at 9 a.m. And his A&E series, tentatively named Lachey’s Bar, is slated to premiere in 2015.

— Jennifer Garcia