Kim Kardashian’s Birthday Post To Chicago Comes Right After She Announced Some Major News — PHOTO

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It's a big week for the Kardashian-West fam — just ask the youngest member. It's hard to believe that Chicago West is already a year old... and at the same time, the world is just finding out that she's about to become a big sister. On Tuesday, Kim Kardashian celebrated Chicago's first birthday with the sweetest post on social media less than 24 hours after confirming that she and Kanye West are expecting baby number four.

Kardashian shared her birthday wishes for her youngest child in a tweet, featuring a truly adorable black and white photo of Chicago (who is currently showing off lots of curly hair). In the photo, she's laying on a bed, and she seems like a total natural in front of the camera — just like her mom (and her brother and sister).

"Happy Birthday to my baby Chi!!!!" Kardashian wrote. "The sweetest baby in the whole world! Mommy and Daddy love you so much!"

Being that it was just over a year ago that everyone was speculating which Kardashians were pregnant, it's wild to think that now, those three babies are all turning one in 2019, and Chicago is the first to reach that milestone.

Chicago has already gotten so big, and the older she gets, the more she looks like her big sister, North. How is it possible that she's already one?

But Chicago's birthday is only part of the big things that the Kardashians have going on this week. After some speculation over the past few weeks, Kardashian finally confirmed that she is, in fact, expecting a baby boy sometime this year — although she didn't share when her surrogate is due. All she said was that the baby will be here "sometime soon," so knowing that a new addition will make his grand entrance at literally any time is very exciting.

And as for all that speculation? That's because Kardashian actually told people about the baby at her Christmas party on accident, and news spread very quickly.

"I got drunk at our Christmas Eve party and I told some people and I don't remember who I told," Kardashian said. "I never get drunk."

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No matter how it got out, the good news is official, so it's time to get excited about what a fourth baby will mean for Kardashian and West — and the three kids they already have. At this point, Saint is outnumbered by his sisters, so he'll probably love having a little brother. And it goes without saying that this is a pretty lucky baby. Have you seen the kind of birthday parties the Kardashians throw for their kids? This little guy has won the family jackpot.

As Kardashian's family continues to grow, it will be so much fun to follow their journey on Keeping Up With The Kardashians. North and Saint already totally steal any scenes they're in, so it's going to be interesting to see what Kardashian's brood of four will be like in action.