"One day when [Tristan] came home from practice, we decided to just do it!" Khloé Kardashian writes of the low-key photograph she shared Dec. 20

By Jen Juneau
March 06, 2018 04:25 PM

Khloé Kardashian is finally revealing the story behind her gorgeous-yet-simple pregnancy announcement photo.

The Keeping Up with the Kardashians star and boyfriend Tristan Thompson starred in the black-and-white snap she posted Dec. 20 — and notably, only their hands were visible as they cradled the mom-to-be’s bare baby bump.

“One day when [Tristan] came home from practice, we decided to just do it!” Kardashian, 33, writes on her website and app, adding of her friends, “Simon took the photo and Savas was on the phone with Hrush and they were directing the placement of our hands.”

“Our heads are cropped out because we both looked crazy, LOL,” she adds. “Everyone thought this was some strategic picture, but in fact, I think we got it done in 20 seconds — and it was just done by us.”

Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.

Kardashian wore a Calvin Klein bra for the confirmation photo, writing, “My greatest dream realized. We are having a baby! I had been waiting and wondering but God had a plan all along. He knew what He was doing. I simply had to trust in Him and be patient.”

A month later, the mom-to-be starred alongside all four of her sisters (including a then-pregnant Kylie Jenner) in a casual ad for the brand.

The KarJenner sisters pose for Calvin Klein
| Credit: Willy Vanderperre for Calvin Klein

The Revenge Body star revealed on Sunday’s season finale of KUWTK that she and her Cleveland Cavaliers star beau, 26, are expecting a daughter.

Although the mom-to-be had initially been hoping for a baby boy, she is now thrilled to be thinking pink.

“God gives us what we need! His timing is never wrong! my hormones were IN RARE FORM for that news,” she tweeted after the episode. “I am now so excited my daughter will have forever best friends with Chicago and Stormi!! God is great!!! Thank you Lord for our princess.”