Hailey Bieber Was 4 Months Pregnant When She Secretly Shot Saint Laurent's New Campaign With 'Little Bean' in Her 'Belly': Photos

Hailey Bieber can do it all — even while pregnant for the very first time !

On Monday, June 3, the model revealed an unknown secret behind a photoshoot she did with Saint Laurent as the face of their latest collaboration with Ray-Band.

"Shot this 4 months pretty with little bean in my belly ," the wife of Justin Bieber informed her Instagram followers while re-sharing the campaign announcement and an accompanying snap.

In the photo, Hailey sported a khaki-colored strapless jumpsuit with brown pointed toe heels.

The ensemble was complete with a belt, black YSL tote bag, large statement earrings and matching bangle bracelets as she wore her brunette hair fully down in a natural style.

In another image from the photoshoot, Hailey posed in the same pair of chic shoes, though this time she donned a long-sleeved, cargo-style jumpsuit and held a brown YSL bag in her hand.

A third shot featured Hailey in an all-black outfit — complete with a long-sleeved button-up and simple trousers.

In the photos, it wasn’t noticeable that the Rhode Skin founder was pregnant , however, the selected styles seemed to ensure her stomach wouldn’t be exposed to the cameras in the slightest.

Hiding her tummy was something Hailey reportedly did for the first six months of her pregnancy , as she and Justin waited until just last month to reveal they were expecting their first child together.

The longtime lovers announced the news on Thursday, May 9, when they simultaneously shared a sweet video of the spouses renewing their vows.

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In the clip, Hailey debuted her baby bump while wearing a white laced gown.

At the time, a source told OK! the brunette bombshell was roughly six months along and would soon be entering her third trimester .

Since spilling the news to her and Justin's fans, the mom-to-be has provided a few updates for her supporters — including confessions related to her pregnancy cravings and adorable snaps of her growing baby bump.

"Currently my biggest craving ," Hailey shared via her Instagram Story last month alongside a photo of her questionable snack creation. "Egg salad on top of a pickle with hot sauce, and no, you’re not allowed to judge!!"

Hailey and Justin have seemed happier than ever in the weeks after revealing their exciting news.

Following the pregnancy announcement, the lovebirds jetted off to Japan for some quality time together as a pair before becoming a family-of-three.