Katherine Heigl is excited about starting a family with Josh Kelley .

Heigl, 29, tells Extra . "We've talked a lot about it, like, 'Are you having any second thoughts here?' " she says. "And he's like, 'No, I'm so ready for this to happen.' It's already been 18 months of planning, and we're both just ready for this to happen already."

"I'm super excited to start a family," Heigl tells Extra. "I've always wanted a family, a large family. But I say that now!"

In a separate interview with Entertainment Tonight, Heigl says she wants to be a mom in a year's time. Kelly, though, is pushing for two years, PEOPLE reports