It's getting harder and harder for Irina Shayk to cover up her baby bump!

Not surprising, the 31-year-old supermodel's maternity style was on point as she was spotted shopping on Melrose Avenue in West Hollywood, California, on Tuesday wearing a leather motorcycle jacket over a loose-fitting black top that matched her skinny jeans and boots.

WATCH: Pregnant Irina Shayk Takes Driver's Ed Lessons in Los Angeles

An eyewitness tells ET that Shayk -- who was wearing minimal makeup -- "spent two and a half hours trying on pieces inside WildStyle Clothing store." The eyewitness says the mother-to-be left the store with approximately 30 shopping bags, which her security guard carried for her.

ET first confirmed in November that Shayk and her boyfriend, Bradley Cooper, were expecting their first child after she debuted her burgeoning belly while walking in Victoria's Secret's annual fashion show.

Months later, Shayk was seen wearing an emerald ring on that finger, thus sparking rumors that she and Cooper, 42, were planning to wed. The couple, who have been dating since May 2015, have yet to comment on the engagement speculation.

While Shayk has been pretty good about hiding her bump, it was on full display when she recreated an iconic scene from Ghost for Love magazine's advent calendar while wearing some skimpy lingerie. 

WATCH: Irina Shayk Rocks a Tin Foil Cap and a Skimpy Bikini in Italy with Bradley Cooper

^{Additional reporting by Kayley Stumpe.}