Everything to Know About Sofia Richie's Pregnancy in 6 Clicks

Richie shared with the magazine how scary the journey was in the beginning because of the milestones she had to hit and the tests she needed to undergo.

"I've learned more in the past six months than I have in my entire life," she said. "And also, just like what the female body is capable of. Every week brings new things, whether it's hormonal shifts or expansion — there's just so much our bodies go through, and it's so interesting to experience it all."

Richie noted her baby girl is growing "pretty fast."

"I was about four weeks pregnant," she disclosed of when she first found out she was expecting baby No. 1. "I was on a trip to Milan for fashion week, and I was going to the Prada show. I was doing a really quick 24-hour turnaround, and I felt terrible but didn't think much of it. I thought it was jet lag. I kind of knew it was going to be a boozy night, and I was a few days late on my period, and I wanted to be generally safe, so I took a test."

With the details she gave about the time she found out about her pregnancy, Richie will likely deliver the baby around April or May.

For months, Richie and Grainge kept the good news to themselves for a while because she wanted to "protect that space."

Now, she's thrilled about being a family-of-three in the near future.

"I'm really excited, and I'm looking forward to opening up to those platforms and letting [my followers] know what I've been going through the last six months," she said. "I can't wait to open that door back up."