The 25-year-old rapper allegedly told Jenner that he "can't do this anymore" and broke up with her, per the reports.
Kylie has been keeping a low profile and removed herself from social media for the past few months as rumours began to swirl about her upcoming arrival.
Insiders said: 'He finally plucked up the courage to tell Kylie he's done, that he loves her and will always be around for the baby, but they're not compatible as a couple.
The alleged news comes as a shock as the couple were recently photographed looking loved-up at Kris Jenner's Christmas Eve party. Khloe Kardashian also announced that she is expecting her first child with National Basketball Association star, Tristan Thompson.
The claims come just days after the couple were spotted partying together for the first time in over three months.
In the pictures, that have leaked online, Kylie is seen taking centre stage as Travis, stares broodily behind her.
According to Twitter, Kylie hasn't been MIA lately because she's hiding her pregnancy - instead, fans believe she's been keeping out of the spotlight because she already given birth. Another, auxiliary, theory: Kylie is for sure going to announce the birth on New Year's Eve, so we won't have to wait too much longer. We are having a baby! He knew what He was doing. I am so thankful, excited, nervous, eager, overjoyed and scared all in one! Some have even speculated that, in his photo shared on Kourtney Kardashian's Instagram, the various family members are peering out out of the frame at Kylie and her new baby as we stand to one side. But it's the best bundle of feelings I've ever felt in my life!'
Exhibit C: This garbage Kardashian-Jenner Christmas card (above) with no Kylie.