Despite his Oscar loss, "Aviator" star Leonardo DiCaprio is flying high. He and girlfriend Gisele Bundchen are trying for a baby even though they're not married, say sources.

Leo's been more secretive than Howard Hughes when it comes to his red-hot romance.

Surprisingly, the recent Academy Awards ceremony was the first time the handsome actor and sexy model Gisele, 24, have appeared together publicly.

Spokespeople for both stars say Gisele is not pregnant, but DiCaprio confided to a friend in February that he and his girlfriend of four years were trying to start a family.

"He said he wants a family and that Gisele was trying to get pregnant," revealed a source close to DiCaprio, who lost out to Jamie Foxx for the Best Actor Oscar.

JUST HIT 30
"Leo said he just hit 30, wasn't getting any younger -- and wanted to be a father very soon."

And gorgeous Gisele, who stole the spotlight from many starlets at the Oscars outside Hollywood's Kodak Theatre, is ready to become Mrs. Leo DiCaprio and a devoted mom.

She says she also plans to establish a charity for Brazilian street children in the next two years. Right now, though, the flawless beauty reserves the term "my baby" for her miniature Yorkshire terrier Vida, which lives with her in Manhattan.

But friends believe everything is set to change for the model, who earns a reported $5 million a year.

"I want three children," she confided recently, "but I want to be in a happy marriage."

-- ALEXANDER HITCHEN