After performing on American Idol last night with the Black Eyed Peas, Fergie's face was the topic of rampant speculation on the web that she had gotten some serious work done.

We spotted the songstress out last night after the show celebrating St. Patty's day with her hubby Josh Duhamel and her folks ... and we couldn't help but wonder the same thing ourselves!

Did Fergie plump up her famous face? Or are the rumors that she's pregnant responsible for her fuller look?