I couldn't believe it when I read it...a progesterone mention!
"On Dec. 3, I felt a little uncomfortable but I thought it was just something I'd eaten. It could have been the beginning of something going wrong. I had my blood drawn yesterday, and it showed that my progesterone levels had dropped so something was not right [with the pregnancy]."
http://www.people.com/people/article/0,,20552365,00.html