Katherine Heigl 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.