Kardashian and her baby's father, rapper Kanye West, know the gender of their child but are keeping it a secret. She said she's careful when she goes shopping to not give anything away.
"We buy all white," she said, laughing. "Or we'll go and buy both (girls' and boys' clothing), and then no one will know."
Besides Kardashian's belly, the cast of "Keeping up with the Kardashians" is getting bigger. The upcoming eighth season will include stepdad Bruce Jenner's sons, Brandon and Brody Jenner, along with Brandon's wife, Leah Jenner.
Brandon and Brody Jenner's mom is actress Linda Thompson, who was engaged to Elvis Presley.
Kardashian said it only makes sense to feature her step-brothers on the show.
"Our parents got married when I was 10 years old so people don't see that side of our lives," she said, "but they've been in our lives for so long so it's fun to share that with everyone."