Pregnant Khloé Kardashian Says She'll 'Try to Not Wear Maternity Clothes as Long as Possible'

Khloé Kardashian made her first talk show debut since confirming her pregnancy.

The pregnant Keeping Up with the Kardashians reality star — who is expecting her first child with her NBA boyfriend Tristan Thompson — appeared on Ellen DeGeneres‘ daytime program, The Ellen DeGeneres Show, to talk about her baby on the way.

“At the beginning, the first trimester is the worst and no one knows you’re pregnant yet and you feel the most uncomfortable,” Kardashian said about feeling ill during her pregnancy. “I think once people know you’re pregnant, you get all the excuses. Hopefully I look pregnant, not just fat. It’s hard for me to breathe right now.”

Adding, “I’m gonna try to not wear maternity clothes as long as possible.”

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And being uncomfortable has nothing to do with wearing curve-hugging clothing.

“The baby is on all my organs so I get out of breath just from walking,” she said.

As for why she chose to announce the baby news on Instagram, Khloé told DeGeneres: “I just wanted to do something myself and write something that was heartfelt for me. I’ve wanted to have a baby for so long it’s just the perfect timing. God always has a plan and I just wanted to do it on my time and when I felt comfortable to do so.”

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Thompson is already a father to 1-year-old son Prince Oliver with his ex-girlfriend Jordan Craig.

“[He’s] such a good dad,” Kardashian said of her boyfriend of over a year. “He’s so great just during pregnancy and he makes me more excited too. I’m excited.”

RELATED VIDEO: Khloe Kardashian Shares a Sexy NYE Kiss With Boyfriend, Tristan Thompson

In fact, she said Thompson has been “milking” the pregnancy “for all he can,” including sympathy cravings. “Mainly Jamaican food, it’s just an excuse. He loves chocolate chip cookies. Like bundles of them.”

The Revenge Body host taped her Ellen appearance on the same day she announced on social media that she will be revealing the sex of her baby on KUWTK, which returns on Sunday.

Multiple sources previously confirmed to PEOPLE that Khloé, 33, and Thompson, 26, are expecting a baby boy.

And with a baby on the way, Kardashian also hopes she’ll marry Thompson one day.

“I hope so, we’re not in any rush for that,” she told DeGeneres. “As you know I’ve rushed quite a few things before,” Kardashian added, subtly referring to her ex-husband Lamar Odom, whom she married just one month after they met in 2009.

“Right now, I’m so loving the place I’m in and very happy with how things are going. We talk about it for sure,” she said of tying the knot with Thompson. “What’s meant to be will be.”

Since confirming her pregnancy news last month with a black-and-white photograph of her own hands and Thompson’s wrapped around her bare stomach, she’s been sharing updates with fans — and showing off her baby bump! — ever since.

On Tuesday, she took to Instagram to share a photo of herself cradling her growing belly in a skintight black dress, captioning it: “Officially six months.”

And as she gets closer to her due date, Kardashian is more determined than ever to stay healthy now that she’s going to be a mom.

“Being pregnant, it’s a whole different type of self-care. I still exercise to maintain my sanity and also to feel good about myself, but my workouts are not as intense as they once were,” she said on her website and app.

“I’m also eating differently — of course, I have cravings, but I want to make sure I’m supplying my baby with the proper nutrient. I’m focused on being healthy mind, body and soul for myself and the baby. But, man, I can’t wait to be a beast in the gym already, LOL!”

Meanwhile, her younger sister Kylie Jenner has been leading a more low-key life since news broke in September that she’s expecting her first child with boyfriend Travis Scott. Kylie has yet to confirm her pregnancy publicly.

From not appearing in family photos (including the Christmas card!) more frequently to refraining from social media, Jenner has kept out of the public eye by sticking close to her house in Calabasas.

“Kylie wants to keep a low profile,” a source previously told PEOPLE in October.

“She feels good, but her body is changing,” the source added. “She doesn’t want to be photographed. At the moment, she wants more privacy. She has family and friends come to her house instead so she has company. She’s very excited about the baby, though. She talks about the baby nonstop.”

Another insider told PEOPLE last month that Kylie is “only trusting her closest friends and her sisters right now.”