The biggest mystery of 2017 and the beginning of 2018 has finally been disclosed! Kylie Jenner officially confirmed her pregnancy with Travis Scott by announcing the birth of their daughter.

On Sunday, Feb 4, Jenner took to Instagram to reveal the arrival of her baby girl. The cosmetic mogul posted a heartfelt message apologizing to her fans for keeping the news a secret for so long.

"My pregnancy was one I chose not to do in front of the world. I knew for myself I needed to prepare for this role of a lifetime in the most positive, stress free, and healthy way I knew how," the 20-year-old wrote.

According to E! News, Jenner and Scott welcomed their baby girl on Thursday, Feb 1st at 4:43 p.m, weighing in at 8 lbs and 9 oz.

The Keeping Up With the Kardashians star also shared a lengthy montage of videos following her pregnancy. The video featured a few moments from her pajama brunch-themed baby shower that featured tons of pink roses, a quick glimpse at her, Khloe Kardashian and Kris Jenner in the delivery room moments before she gave birth and Kim and Kanye's newborn daughter, Chicago West made a quick appearance as well.

Since sharing the news on Instagram, Kylie's post has received over 7 million likes and 400,000 comments.

Jenner And Scott's Baby Girl Has Arrived

News about Jenner's pregnancy broke in September 2017, but she never officially confirmed that she was pregnant. She also stayed away from social media the last few months and hasn't made any public appearances. Until on Jan. 22, when the reality star reunited with her sisters for Calvin Klein's Spring 2018 campaign. However she made sure to cover up her frame as she posed alongside her sisters.

A few days later, TMZ shared a photo and video of Kylie and her baby bump. The mother of one was spotted with her best friend, Jordyn Woods, her mother, Kris Jenner and a number of other people at a construction site in Hidden Hills, Los Angeles. Sources close to Jenner claim that she was scoping out the spot, because she is considering making it her new home.

Kylie And Travis

Kylie and Scott linked in April 2017, but things didn't seem to get serious between the two until the couple shared photos of their matching minuscule butterfly tattoos in June 2017.

Then in August 2017, Scott was spotted at Kylie's 20th surprise birthday with her family and friends. In September 2017, TMZ was the first outlet to report that the couple was expecting.

Now that the baby is here, the couple couldn't be happier. According to a source, Travis has been showing the baby off to his crew.

"He seems so happy and just keeps rubbing her head and saying, 'Daddy's here. Daddy's here," the source stated.

Following Kylie's reveal, her mother, Kris Jenner took to Twitter to express how excited they are to continue to expand their family.

"God is SO good!! I am so excited and thrilled to welcome another precious baby girl to our beautiful, ever growing family. We are blessed beyond belief!" Jenner tweeted.