Was it the stress of the Olympic competition? Or stress from living in the sex-crazed party known as the Olympic Village?
Nope. It's because she was five weeks pregnant.
"When I was throwing my body around fearlessly, and going for gold for our country, I was pregnant, and [Monday] I'm 11 weeks pregnant," she told Matt Lauer on the Today show on Monday while sitting with her husband, Casey Jennings.
"I?m a pretty happy girl and I was unreasonably moody," Walsh Jennings said Monday. "I thought it could have been the stress of the games, and travel kind of throws your schedule off, but I knew. At some point, you're late and then you start feeling something. And I definitely started feeling something in London."
The baby, due April 9, will join the couple's sons, Joey, 3, and Sundance, 2.