How Chrissy Teigen found out she was pregnant with baby No. 3

Chrissy Teigen is setting the record straight on her pregnancy story.

After confirming that she and her husband, EGOT winner John Legend, are expecting their third child together, a curious fan took to Twitter to explain how she was "confused" about Teigen's pregnancy timeline because the model had recently undergone breast reduction surgery.

"Oh, it's quite a story. lol," Teigen replied before getting into the details in a thread. "I did the routine pregnancy test you do before surgery. It said negative. It was not negative."

The 34-year-old said she took another pregnancy test on her own "a few weeks after surgery" on June 19.

"So the morning of John's album release, he wakes up at 3am to do good morning america. I woke up with him and was like man, should take my monthly test to be disappointed... I was not disappointed. But I was scared s---less," she explained.

"Was pretty positive you shouldn't get your boobs out while pregnant?" she continued. "Pretty sure."

Teigen added that she was shocked to find out she was pregnant because "I didn't think I could get pregnant naturally anyway." The couple's two children -- daughter Luna, 4, and son Miles, 2 -- were both conceived through IVF.

"But what they say so often can be true," she added. "When you give up on trying, life has a way of surprising you."

WATCH: Chrissy Teigen's advice to my younger self (and my kids)

3:03

Chrissy Teigen's advice to my younger self (and my kids)

Even the no-filter supermodel, businesswoman and mom has some advice she'd tell her younger self through the years.

Speculation that Teigen was pregnant first began on Aug. 13 after she was seen cradling her belly in the music video for Legend's new single, "Wild." She later confirmed the news on social media.

While rocking some black leggings that showed off her baby belly, Teigen said, "Look at this third baby s---... Oh my God."