The star pretty much disappeared from social media for months, leading fans to look for clues she was expecting.
Kylie explained why she’d kept it a secret, saying she wanted to prepare for being a mum in a “stress-free way”.
Now the 20-year-old has officially announced the birth of her daughter – here’s what we learned from her video.
The 12-minute video titled To Our Daughter shows Kylie’s journey throughout her pregnancy.
It was uploaded to YouTube on Sunday and in less than 24 hours has racked up more than 20 million views.
In it, we see lots of footage of her taking selfies and videos with her bump as well as clips of her attending scans with her rapper boyfriend Travis Scott.
She also unexpectedly ditches her iPhone in favour of videos shot on a camcorder.
Not only was the video the premiere of her child’s birth, it was also the first time we got to see a glimpse of her niece Chicago.
Kim Kardashian-West and Kanye West announced the birth of their third child by a surrogate in January.
They’ve yet to release any photos of their daughter but the video shows Kim introducing Chicago or Chi, to Kylie for the first time.
The family aren’t ones to sell photos of their children and instead aim to be the first to hit the upload button.
Kim and Kanye chose to share the first photos of their son Saint on Kim’s app and website, while North’s first photo appeared on Kris Jenner’s chat show, when Kanye was appearing as a guest.
The Kardashians are no strangers to themed baby showers complete with matching pyjama sets for all the guests and Kylie’s was no different.
There’s more pink, peach and satin than you’d find at any posh spa.
“I love you and I love your mum, she’s going to take amazing care of you and you are one lucky girl to be able to call Ky your mum,” a friend says, talking to the baby.
Kylie also poses for a photo with another friend who was expecting at the time.
“We used to talk about this [being pregnant at the same time] two years ago as a joke,” she says.
“I was like Heather you’re next baby, wait for me.”
Despite being surrounded by family, Kylie’s dad Caitlyn Jenner doesn’t make an appearance during the video.
In fact, the former Olympian was spotted on the red carpet at the Xposé Benefit Beauty Awards in Dublin on the day Kylie announced she’d given birth.
Fans have since been speculating whether there’s a family feud going on, or just an unexpected arrival.
The video was narrated by her best friend, model Jordyn Woods, who starts the video with a message directly to Kylie’s daughter.
“Whatever your name is going to be, this is how I found out about you,” she says.
It also included cameos from Kylie’s nearest and dearest like mum Kris, sister Kim and moments with Travis Scott’s family.
For many people, keeping the news of a baby secret for just 12 weeks is too large a burden to bear but her friends and family managed to keep quiet for nine months.
It’s safe to say people on the internet are not sure many others would’ve been able to do the same.