Pregnant Heidi Montag Pratt Shows Off Baby Bump at 26 Weeks in Black Bodycon Dress

Heidi Montag/Instagram

Heidi Montag Pratt is getting ready to enter her third trimester of pregnancy.

The pregnant reality star, 35, who is currently expecting her second baby with husband Spencer Pratt, shared a new photo of her baby bump on Instagram Tuesday, announcing that she's currently 26 weeks along.

Heidi snaps a mirror selfie while holding one hand on top of her bump, which is accentuated by her black bodycon dress.

"The most beautiful," fellow The Hills star Kristin Cavallari commented on the picture.

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Oxana Alex/MEGA

RELATED: Pregnant Heidi Montag Pratt Shows Off Her Baby Bump in Nude Maternity Shoot — See the Photo!

Last week, Heidi shared pictures from a new maternity photo shoot in which she posed nude for several shots.

Captured by photographer Oxana Alex, the photo showed Heidi as she stood fully nude in front of a dark background while cupping her breasts with one hand and cradling her baby bump with her other.

The image, obtained by PEOPLE, appeared to be from the same photoshoot that The Hills: New Beginnings star took part in and previously documented on her Instagram feed.

"Thank you @oxanaalexphotography for capturing this moment of time, embracing the beauty and transformation during #pregnancy," Heidi wrote alongside a video of herself posing in an oversized pink tulle robe in front of a complementing floral backdrop.

Heidi and husband Spencer, 39, confirmed to PEOPLE in June that they are expecting their second baby, a boy. The couple is already parents to 4-year-old son Gunner Stone.

While she isn't due until December, Heidi believes that her little one will make an early arrival, much like her Gunner did back in October 2017.

"Gunner was three weeks early, so I'm anticipating that to be the norm. I've asked my doctor, like, 'Is that a reoccurring situation?' Basically, she said, 'Yes,' " Heidi recently explained to PEOPLE. "So if your body naturally kicks out babies early, you'll tend to do that."