Kaley Cuoco's baby bump made a cameo while the expecting mother filmed for her upcoming series Based On A True Story.

The 37-year-old actress showed off her growing baby bump in three casual and comfortable outfits while on set in Los Angeles on Thursday.

The Big Bang Theory alum - who revealed last year that she is expecting her first child with boyfriend Tom Pelphrey - donned an all-black outfit as she arrived and stepped out of her car.

She wore a simple, black long-sleeved top paired with black sweatpants.

The California native tied her brunette tresses up in a messy bun and shielded her eyes with a pair of retro vintage round sunglasses.

After costume and makeup, she changed into an oversized blue track jacket over light gray top in one look.

She also sported a pair of darker gray oversized sweatpants and metallic pink puffy sandals.

The 8 Simple Rules actress' brunette tresses and bangs were curled in voluminous and messy waves.

For another scene, the expecting mother kept the same hairstyle but changed into a classy and chic business casual ensemble.

She sported a light gray, double-breasted trench coat thrown over an outfit featuring wide-leg trousers and white loafer mules. 

The comedy thriller was ordered by Peacock in April 2022.

Four months later, Cuoco was cast in the main leading role and will play the role of a realtor named Ava Bartlett. 

Shortly after, production started for the show, and since then, a release date for the series has not yet been announced. 

Based On A True Story is an upcoming show inspired by a bizarre true event, according to the synopsis.

The series is about a realtor, a plumber, and a former tennis star whose lives collide in a story that explores America's obsession with serial killers and true crime.

Last October, The Flight Attendant star announced that she was expecting a baby girl with the 40-year-old actor after they confirmed they were dating just five months prior to the news.

This will be both Cuoco and her boyfriend's first child.