Kourtney Kardashian opened up to Us Weekly about the challenges of her third pregnancy, while Khloe joked that she gained all of her big sister's pregnancy weight. Credit: Paul Zimmerman/Getty Images

Katching Up with Kourtney! Kourtney Kardashian opened up to Us Weekly about the challenges of her third pregnancy on Monday, Oct. 27, assuring Us that it's still been relatively easy.

"I feel good," the mom to Mason, 4, and Penelope, 2, told Us at the junket for her spin-off series, Kourtney & Khloe Take the Hamptons, in L.A. The only struggle she's dealt with has been general fatigue while expecting her third child with boyfriend Scott Disick. "I went to a wedding [of restaurateur Scott Sartiano and model Allie Rizzo] Saturday night, and then yesterday I was just so tired the whole day. Any little thing takes a toll on me."

Kourtney recently took her little ones to a theme park, which according to the reality star, knocked her out for several days. "I went to Disneyland for 10 hours… I usually go for at least 12, but that took like, two days [to recover]."

Still, the eldest Kardashian daughter gushed to Us that she loves being a mom — pregnancy and all. "I was tired, but it was so worth it," Kourtney said. "I feel tired but in general, I do love being pregnant and always feel pretty good. I'm lucky. I always hear, like, horror stories."

Younger sister Khloe Kardashian chimed in and told Us: "A lot of my girlfriends hate being pregnant." She added that most couples struggle due to hormonal side effects from pregnancy. "I guess it's really common to hate your partner when you're pregnant," Khloe told Us, "I hear so many negative things [from others]."

But not her big sister! "She's so great pregnant and looks so great pregnant," Khloe said to Us about Kourtney. "And it's just so easy for her."

The hilarious youngest Kardashian sister joked, "I gain her pregnancy weight… which sucks. In the Hamptons, I blamed her for everything. I would eat everything she ate. It was horrible."

Kourtney, meanwhile, reflected about why she chose the Hamptons to shoot for this year's excursion. "It was the perfect place to be," she told Us. "Being in such a relaxing place, I think, with the kids and to be able to relax — it was so beautiful. I mean, we really have been talking about it for years." Kris Jenner's eldest noted that she was open to the possibility of filming again at the luxurious East Coast destination in summer 2015.

Us exclusively broke news of Kardashian's third pregnancy in June — which Kourtney confirmed herself on season nine of Keeping Up With the Kardashians. The brunette stunner will soon have another mini-me; multiple sources confirmed to Us this past month that she's expecting a baby girl.

Kourtney & Khloe Take The Hamptons premieres on E! Sunday, Nov. 2 at 9 p.m. ET.