Celebrity news website TMZ, People magazine and Buzzfeed all quoted sources as saying that Jenner, 20, the half-sister of Kim Kardashian, is expecting a baby with her boyfriend, the rapper Travis Scott.
Jenner's representatives could not be reached for comment.
Jenner, who has parlayed her family's reality TV show and a 97 million Instagram following into a lucrative cosmetics line, later posted a Snapchat photo in which she appeared to have a baby bump under an oversized black T-shirt.
People magazine, quoting unidentified sources, said the baby was due in February.
"The family has known for quite some time. She is really excited and so is Travis!" the magazine quoted one source as saying.
Another source said to be close to the family told People: "It is an unexpected, but completely amazing turn of events that she could not be more excited or thrilled about."
Jenner and Scott, 25, have been dating since April.
source: news.abs-cbn.com
