Uchitel, 36, and Hahn, 26, married in Nevada in early October. It was Uchitel's second marriage -- she briefly tied the knot with Wall Street trader Steven Ehrenkranz in 2004, though the union only lasted for four months.
In 2001, Uchitel was engaged to businessman James Andrew O'Grady, who died in the Sept. 11, 2001 attacks on the World Trade Center.
Uchitel became a tabloid sensation in 2009 when it was discovered that she was a mistress of squeaky clean golf legend Tiger Woods.
Uchitel and Hahn, a businessman and former Penn State football player, met in November 2010 and quickly moved in together, before relocating to San Francisco.
"She found out she was pregnant when she auditioned for 'The Amazing Race,''' the source alleged. "'They were going to try out to be a couple on the show, and when she had a drug test, it came back positive that she's pregnant."