Kardashians In Khaos Over Rob & Blac Chyna's Baby News — 'It's The Ultimate Payback!'

Is another Kardashian on the way? RadarOnline.com has exclusively learned Rob Kardashian's family has gotten wind he and his fiancée Blac Chyna are expecting a baby!

"Blac was desperately trying to get pregnant and the family fears she already might be," an insider revealed.

The reason? "They're all scared that he proposed so quickly because he felt pressured because she could be pregnant," said the insider.

While all of 29-year-old Kardashian's family is upset, Kylie Jenner and Tyga are "beside themselves" over the tense situation.

"Kylie had a breakdown over it," said the insider of 18-year-old Jenner, who has been involved in a vicious ongoing feud with her boyfriend's baby mama, who could now become her sister-in-law.

"The family fears it was Blac's plan to get pregnant all along," said the insider. "She doesn't really love Rob and it would be the ultimate payback to Kylie and the rest of the family for all the fights they've had."

And Kardashian seems to be a willing victim of 28-year-old Chyna, who "uses sex to manipulate men," noted the source. "Blac's completely got Rob under her spell and the family hates it."