Another day, another false baby alarm.

Scarlett Johansson went jogging with beau Sean Penn near his Malibu, Calif. home on Sunday. And while fans have grown used to seeing the hot new couple (who've slowly gone public with their romance) out and about together, there was something new about Johansson, 26: a baby bump?!

PHOTOS: Stars who really are expecting

Nuh-uh, her rep tells

"Scarlett is not pregnant," the rep says in a statement.

What about that supposed "bump" that appears in the photos?

PHOTOS: Can you believe these couples' age differences?

"She's outside running and it's simply the placement of her shirt that is misleading," the rep explains.

"She's been training for The Avengers for over 4 months and is in the best shape of her life."

VIDEO: Scarlett speaks out for Planned Parenthood

Meanwhile, Johansson and Penn, 50, are stronger than ever.  The Iron Man 2 actress took Penn as her date to Reese Witherspoon's recent nuptials -- and they made out at a local bar afterwards.

And Penn has the support of at least one ex. "They're great together!" Sports Illustrated model Jessica White, who dated Penn in 2009 and 2010, said recently.   "Sean is a really lovely man...[he] needs a good woman in his life."

Get more Us! Follow us on Twitter, Friend us on Facebook, Subscribe to Us Weekly