Jessica Simpson says second pregnancy was unplanned, wedding dates pushed back

Jessica Simpson does plan to walk down the aisle with her fiance of two years, Eric Johnson. She just doesn't want to do it pregnant. The pop star and fashion mogul, who just signed on to star in an NBC sitcom pilot based on her life, says that she and Johnson have set two wedding dates -- but both times, they've had to be postponed because she didn't want to wear a maternity wedding dress.

"We've had two different wedding dates, but he keeps knocking me up," Simpson told Jay Leno on Tuesday night. "We're doing it very backwards, I know. I mean, he's got -- I'll just keep my legs crossed, I guess, this time."

The Weight Watchers spokeswoman admits that she didn't plan her second pregnancy, particularly so soon after their first daughter, Maxwell Drew Johnson, was born. "Apparently it was a part of God's plan for my life," she says. "I was extremely shocked."

She admits that she gained too much weight during her first pregnancy and plans to be more careful this time, sticking to her Weight Watchers plan. "I was really happy to be pregnant and I didn't ever step on the scale. I didn't realize you could gain that much weight that quickly ... I didn't really make any healthy, good decisions."