That's what all the fans are trying to find out after the story and a photo of Stewart's little round belly appeared in an Australian publication, News Weekly.
The story has now been picked up here in the U.S. and was touched upon by the New York Daily News.
Although, talk about a shocker and a publicity magnet, no one has yet to confirm or deny the story.
The Australian Weekly's insider says, "When [Stewart] worked out she was late, she obviously started to thinking that she could be pregnant. And because of the timing, she thinks Rob could be the father."
"THINKS Rob could be the father", there's another mystery to follow up.
It went on to say that Kristen had a friend to purchase a home pregnancy kit for her and that she's "very nervous about the whole situation."
Kristen has been working on the film, "The Runaways".
Thus far neither the stars of the Twilight series nor their representatives are commenting.
What would this do concerning the series of movies?
At least most reporters say they personally think this is a publicity stunt, not by the actors as they do not need any, but perhaps the Aussie publication needs some sales.
Better stay tune to the Hollywood grapevines as this will come out as both true and false.