The 20-year-old reality star and business mogul is due in February with her first child with rapper Travis Scott.
Kylie began dating Travis back in April following her split from former long-term boyfriend Tyga, who has a child, son King Cairo, with Blac Chyna (Rob Kardashian’s ex).
“They started telling friends a few weeks ago,” says the source. “The family has known for quite some time. She is really excited and so is Travis.”
Another source close to the family said: “It is an unexpected but completely amazing turn of events that she could not be more excited or thrilled about.”
“Everyone is overjoyed for her,” says the source. “This is the happiest she’s ever been.”
Another insider says Scott, 25, began telling friends about the pregnancy in July. “He was so excited he couldn’t keep it in,” says the insider. “He’s been so affectionate and protective of Kylie since they found out. He can’t wait to be a dad.”
The insider adds Jenner was worried people would find out she was pregnant before she was ready to share the news, so she “started posting old photos of herself on social media” that flaunted her flat stomach.
“Kylie was really surprised but is so happy,” says the insider. “She wants to be a mom.”
“Kylie broke up with Tyga partly because she felt too young to get serious,” says the insider, who adds there are “no plans” currently for Jenner and Travis to wed. “Now she’s having a baby with a guy she just started dating. People around her are really surprised. It happened really fast, but for Kylie, being with Travis is so different than anyone else. She’s so in love with him. She’s really excited.”
The star’s baby won’t be the only new member joining the famous KarJenner brood: Jenner’s older sister, Kim Kardashian West, is also expecting via surrogate. Kardashian West shares two other children with husband Kanye West, Saint, who is 21 months old, and daughter North, who turned 4 in June.
Though Jenner and Scott’s relationship is still rather new, her family is definitely on board with the romance: A source told heartbeat live.com in August that the KarJenner crew “loves Travis.”
“Kylie and Travis are doing great,” said the source. “There’s no drama with Travis. He’s a cool guy.”
“He treats Kylie with a lot of respect and love,” added the source. “Kylie is very happy.”