Twi-hards are in for the shock of their lives, if the word of one Australian tabloid is to be believed.

The real-life secret romance between Twilight stars Kristen Stewart and Rob Pattinson is in turmoil after Kristen discovered she could be in the early stages of pregnancy with the actor’s baby.

“When she worked out she was late, she obviously started to thinking that she could be pregnant,” says a pal. “And because of the timing, she thinks Rob could be the father.”

Kristen, who is alsso reportedly dating Michael Angarano, is so nervous over what a pregnancy test could reveal, she sent a friend to the drug store to purchase a home kit.

“Kristen asked one of her friends to buy the test because she was worried about someone seeing her at the drug store,” an mutual friend of the young stars revealed to NW Magazine this week. “She’s very nervous about the whole situation.”

Developing…