Kim Kardashian engaged to Nets' Humphries

Reality TV star Kim Kardashian is engaged to her beau of six months, New Jersey Nets forward Kris Humphries.

"I didn't expect this at all," Kardashian, 30, told People magazine. "I was in such shock. I never thought it would happen at home, and I never thought now." Kardashian's representative also confirmed the news to Us magazine.

The proposal came May 18, in the bedroom of Kardashian's home in Beverly Hills, said E! News. She walked in and saw Humphries, 26, on bended knee with rose petals forming the words "Will you marry me?" the site said.

The engagement ring, a custom design from Lorrain Schwartz, held a roughly 16-carat diamond and two baguettes of about two carats each for a total of 20.5 carats, E! News said. "I just knew I wanted it to be big," Humphries told People.

No wedding date has been announced.

In on the surprise was Kardashian's younger sister, Khloé, who married Los Angeles Lakers forward Lamar Odom in 2009. "I can't believe I was able to keep this a secret but now I can scream all I want about it!" she tweeted Wednesday.