Khloe Kardashian not only confronted NBA star James Harden recently about rumors of his infidelity but is now convinced he isn't telling her the truth about all he's been doing behind her back.

Radar Online reported the 31-year-old Kardashian is telling friends she is "doomed to stay single" after news broke of the Houston Rockets star guard's dalliances with an Australian blonde while traveling abroad sometime last month.

A source insists Kardashian "truly believed she had found a good guy" in the 25-year-old Harden but now doesn't seem quite so sure.

"The chemistry was really strong and intense, and Khloe thought this was someone she could get serious with," a source said.

Rochelle Relf, 23, went public with claims of "hooking up" with Harden since he's been dating Lamar Odom's now ex-wife earlier this month. According to her, the two met at a casino in Sydney, and before long one thing had led to another. She said Harden had been in Hawaii with Kardashian before flying to Australia and winding up spending the night with her.

Relf recalled Harden being "charming" and "affectionate" and asking her if she would visit him in the States. She said Harden told her he was single.

"James denied hooking up with the woman, but Khloe just doesn't believe him," a source said. "Khloe had really wanted to be in a new solid, healthy relationship by the time her divorce was made final. She just feels very unlucky in love."

Kardashian and Odom finalized their divorce earlier this month. The two were married for four years, and Kardashian initially filed to legalize their split in early 2013.

Hollywood Life reported the "Keeping Up With the Kardashians" star may now be pregnant with Odom's child. The 35-year-old Odom played 14 NBA seasons, winning the league's Sixth Man of The Year Award in 2011 and teaming up with Kobe Bryant to win back-to-back titles in 2009 and 2010.