Nikki Bellais bumping along!

In a sweet Instagram post on Friday, the first-time mom-to-be, 36, shareda series of photosof herself with fiancéArtem Chigvintsev, where she sat on his lap and he had his hand placed on her belly.

“Still have some abs, but my bump is gettin’ bigger,” she told the camera in video footage posted before the selfies,showing her bare belly fromthe side. “How cute. It’s like right here at the bottom. I love it.”

Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Nikki Bella/Instagram

Nikki Bella Pregnancy

Nikki Bella Pregnancy

Nikki Bella Pregnancy

Nikki Bella Pregnancy

RELATED GALLERY:The 21 Cutest Photos of Pregnant Twins Nikki and Brie Bella with Brie’s Daughter, Birdie

Nikki and her twin sisterBrie Bellarevealed their pregnancy news exclusively to PEOPLE on Wednesday, further sharing that they’re due within just a week and a half of each other.

“[It was] a total surprise,” Nikki said of the news, while Brie said themgetting pregnant around the same timewasn’t planned. “It took evenmea good week to come to terms with like, ‘Oh my gosh, I’m pregnant.’ I’m not ready for it.”

Nikki and Brie Bella.James White

Brie and Nikki Bella

RELATED VIDEO: Brie Bella Didn’t Talk to Nikki for a Week After Finding Out They Were Both Pregnant

Brie didn’t talk to Nikki for a week after learning about the pregnancy (which she almost thought “was a joke” at first). “It was just too much and to think I was also pregnant and my hormones are going crazy,” said Brie, who’s also mom to 2½-year-old daughterBirdie Joewith husbandDaniel Bryan. “I think that’s why that came out.”

Also on Wednesday, Nikki was photographed for the first time since her pregnancy announcement out and about in Los Angeles, on her way to pay a friend a visit.

For the outing, the mom-to-be wore a pair ofhigh-waisted black leggings and black sports braunder a sheer mesh red tank top. Nikki wore her long dark hair down straight over her shoulders, and accessorized in large sunglasses and gray sneakers with pink laces. At one point, she placed her hand on her belly.

source: people.com