Ashlee Simpson isn't engaged

Ashlee Simpson isn't engaged... yet - and the band she's been sporting on left-hand ring finger is a promise ring from her Fall Out Boy beau Pete Wentz.

"It just means that he hasn't asked my dad yet..." she explained on Fuse TV's The Sauce while promoting her new album 'Bittersweet World'.

Simpson also dashed rumors she is expecting her first child - insisting: "No, I'm not pregnant!"

Though Ashlee and Pete may not be walking down the aisle, her older sister Jessica — who heads to Kuwait to perform for the troops next month — may be.

A close pal of her boyfriend, Dallas Cowboys quarterback Tony Romo recently told Us Weekly, "I think they're going to get married."

A rep for 23-year-old Ashlee would only say, "She is not engaged."