J.Lo at 40: How a Diva Was Made!

In 40 photos, see how the birthday girl (on July 24) went from Jenny from the Block to superstar

A TELLTALE BUMP

While on the El Cantante tour with hubby Marc Anthony, a wind machine offers a glimpse underneath Lopez's flowing Roberto Cavalli-designed costume – revealing a prominent baby bump at the Oct. 3, 2007 stop in Uncasville, Conn. "I used a lot of stretch fabrics," Cavalli tellingly tells PEOPLE of his tour outfits.