Christina Milian is four-and-a-half months pregnant, the singer confirmed to PEOPLE as she celebrated her 28th birthday at the MGM Grand’s Tabu Lounge in Las Vegas on Friday night.

The “Dip It Low” singer eloped with hip-hop musician-producer The-Dream in Sin City last month.

“My husband and I are expecting,” she said, showing off a baby bump under a loose green dress, topped off with silver accessories. “We’re really excited.”