A source reveals the real reason Kylie Jenner is trying to keep her pregnancy very private.

The youngest daughter in the Kardashian-Jenner clan, Kylie, has been on the spotlight since "Keeping Up With the Kardashians" premiered in 2007. She was just 10.

The family has been a part of millions of American households for years, and fans have become used to knowing every detail -- important or minor -- about the famous first family.

It took Khloe Kardashian months to confirm her pregnancy, which was rumored to be around the same time Kylie conceived. When the older Kardashian announced her baby news in mid-December, fans thought Kylie would soon follow suit. But Christmas and New Year came, and still nothing.

It is best not to expect any pregnancy news from the 20-year-old reality star anytime soon, as a source says she does not plan on giving any.

"She's very happy about the pregnancy but she doesn't want to share this with the world," the insider told Us Weekly.

The source explained that Kylie's decision to go underground since she found out that she is carrying her first child with boyfriend Travis Scott is a "personal preference." "She wants to keep this one aspect of her life private," the insider added.

The source also defended Kylie's actions, saying it was the first thing she wanted to keep to herself since becoming a reality star. "She's worked hard enough to do whatever she wants," the source quipped.

Describing Kylie as "very stubborn," the insider shared how she is known for sticking to her choices. "This is a decision she made early on in her pregnancy and she's sticking by it."

According to another source, the lip maven, who is reportedly six months along, has already prepared the nursery for her future baby. She has also baby-proofed her Hidden Hills mansion and taken out all sharp objects.