Jennifer Aniston Pregnant - with Twins?

Jennifer Aniston's reps have already denied that she's pregnant, but Star Magazine is still running with their story.A few weeks back the magazine claimed that Jenn was pregnant with John Mayer's kid, and now they're claiming she's having twins!Apparently Jenn has been undergoing fertility treatments in a bid to get pregnant before her 40th birthday. "She knows her baby-making years are limited,"