Credit: Jon Kopaloff/FilmMagic

Autumn Reeser had her reservations about slipping into a slinky LBD for her appearance on Jimmy Kimmel Live! Tuesday.

"I was a little nervous about wearing it," she explained. "It's a little tight and I'm carrying a little extra weight."

But the No Ordinary Family star's waistline isn't suffering from lack of exercise: "I'm pregnant!" she announced just before pointing to her tiny baby belly.

Married to writer-director Jesse Warren since May 2009, the 30-year-old actress has already devised a plan to incorporate her pregnancy into the hit ABC series.

"My character is not so great with men, but it is a superhero show, so it could be a magical something that just happens," Reeser mused. "You never know -- stranger things have happened!"

If that doesn't work out, the actress assumes that her character, a nerdy lab technician, will likely be "standing behind large piles of books" for the duration of the show's first season.