"I'm obviously so happy for them, but if anything I loved the privacy," the reality TV star said.
But that bit of privacy went out the window when Kardashian's boyfriend, Kanye West, revealed during a December 30 concert in Atlantic City, New Jersey, that they were expecting their first child.
Now, Kardashian (32) says her motherly instincts have made her pull back from being so open about her personal life.
"I think that definitely kicks in where you're like, 'OK, I have to go in protect mode' and as ironic as it sounds, you live your life on a reality show but then when you grow up ... certain things change your life that make you want to be more private and this is definitely one of them," she said.
Kardashian married basketball player Kris Humphries in August 2011 and their divorce is not finalised. West rarely grants interviews and the 35-year-old rapper is the ying to the Kardashian family's "out there" yang. Kim says she is somewhat influenced by West's approach.
"When you spend time with someone, you learn things from them, so I see what (his) views are in wanting to be private, so that's a choice we make together as a family just in how we're gonna raise our kid," she said.
Kardashian's baby is due in July. A new season of her reality show with her sister Kourtney, Kourtney And Kim Take Miami, begins on Sunday on E!