"It was so hard to keep it a secret," the 36-year-old singer told the magazine. "I was worried I'd start throwing up on set [of Bravo's Going Platinum] and everyone would be like, 'Oh, she's pregnant.'"
Jewel, now in her second trimester, wed rodeo star Murray, 41, in the Bahamas in 2008, and the couple has been trying to have a baby for two years.
"I have always been a workaholic, so I had to learn how to slow down and take care of myself in a different way," Jewel said of her struggle. "I'm trying to be in the moment and really enjoy my pregnancy."