Khloé Kardashian faces scary pregnancy struggles after doctor's visit

A sneak peek at Sunday’s brand new episode teases an upcoming doctor’s visit for the mom-to-be — and some potentially scary complications.

“Literally, I can’t walk,” she tells sisters Kim and Kourtney Kardashian.

“Can you text your doctor right now?” suggests Kourtney, 38.

Kardashian, 33, is currently expecting her first child, a baby boy, with boyfriend Tristan Thompson. (The Cleveland Cavaliers player also has a 1-year-old son named Prince Oliver from his previous relationship with ex Jordan Craig.)

“They are absolutely thrilled,” a source previously told PEOPLE of Kardashian and Thompson, 26. “This is something Khloé has wanted for years and years and yet it’s more than that: She didn’t want it unless she was in the right relationship for it.”

“This is such a wonderful moment for her: not only is she going to be a mother, she is going to be raising a child with a man she truly loves,” added the source. “Everyone is over the moon for them both.”

Since the reality star publicly confirmed her pregnancy news in December, she’s been regularly sharing updates with fans — and showing off her growing baby bump!

“She can’t wait to be a mum,” a source recently told PEOPLE. “She is excited about being pregnant, but can’t wait to meet her baby.”

Keeping Up with the Kardashians airs Sundays (9 p.m. ET) on E!

This article originally appeared on PEOPLE.