Amanda Peet: Preggo!

Us Weekly has learned Amanda Peet, 34, and her fiancé, screenwritter David Benioff, are expecting their first baby.

“She’s almost 12 weeks along. She’s thrilled,” says the source, who adds the two will tie the knot this month in New York City. The couple have been engaged since July 2005. A rep for Peet could not be reached for comment. No word on whether the pregnancy will be written into Peet’s new NBC series Studio 60 on the Sunset Strip.