'Teen Mom' Star Kailyn Lowry to Kylie Jenner: Enjoy Your Friends While You Can!!!

Kylie Jenner better enjoy her friends while she can ... don't nobody young, single, wild and free wanna hang with a preggo ... so says "Teen Mom" star Kailyn Lowry.

If there's someone who can relate to young pregnancies it's Kailyn, who got knocked up at 17. She tells us being pregnant can very much still be a challenge even if you can bankroll an army to look after you.

But check it out ... it's Kylie's friends who might struggle with her pregnancy the most. As we reported ... Kylie's beyond her years even at just 20. Still ... buckle your seat belt.

TMZ broke the story ... Kylie's having a girl.