Selena Gomez to Be a Big Sister!

Selena Gomez is about to welcome a baby into her life. No, the singer is not pregnant.

But she is about to be an older sibling, as the artist Tweeted with excitement today:

"Momma [Mandy Teefy] and [step-father] Brian are finally letting me share the news. My mommy's carrying my baby brother or sister :) I'm the happiest girl in the world!"

We wish the new family nothing but health and happiness.

In what is now the second most exciting thing to happen to Selena this week, she took the stage at Madison Square Garden with Taylor Swift. Watch the pair's duet of "Who Says" NOW!