12/17/2007 at 04:00 PM EST
can't wait for her wedding day later this month – if only so that the marathon planning might end, and she and Josh Kelley can focus on starting a family.
Heigl, 29, tells Extra
that she's more than ready for her big day. "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."
The last-minute arrangements are proving to be hair-raising, however. "I'm mostly panicking about all the details, and getting there, traveling, transportation, talking to the pastor, getting the license," she says.
Her worst wedding-day fear? "Not being present in the moment, you know?" she tells Modern Bride
magazine. "Like, building it up so much you can't really enjoy the moment you're in."
Once the wedding is over, the Grey's Anatomy
Golden Globe nominee and her musician groom may very well embark on a different kind of planning – for having kids.
"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. Says the prospective mother-to-be: "We'll meet somewhere in the middle."