Khloe Kardashian and Lamar Odom want a baby!

But Kardashian, 27, has struggled throughout her 2-year marriage to Odom, 31, to conceive. "It's so hard. I never knew about ovulation and the limited amount of time that you have to get pregnant," she said while guest hosting the fourth hour of NBC's Today Show on Tuesday, as excerpted by the Daily Mail. "I never knew about that. No one ever taught me that."

VIDEO: Khloe "freaking out" about possible infertility

"We would love to have kids," the reality star continued. "[But] when you have schedules such as ours, it's really hard to hit that mark. So it's frustrating, but definitely. I want to have kids."

PHOTOS: Stars who've struggled to conceive

This isn't the first time Kardashian has expressed her worries about having kids: in an episode of Khloe & Lamar that aired in May, she was "freaking out" about possible infertility.

"I'm sorry for snapping at you and being on edge lately but I've been holding a lot of stuff in and trying not to bother you, but I've been freaking out about why I'm not pregnant," she told her NBA hubby. "It's scary [thinking] "Oh God, what if I physically can't have kids.'" 

PHOTOS: Khloe, Lamar, Kourtney, Mason and all the Kardashians at Kim's wedding

"I help [sister] Kourtney a lot with Mason," she has said. "Kourtney's an amazing mom, but I've raised my little sisters Kendall and Kylie; I know I would be an amazing mom."

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