Kris Jenner is getting another grandchild!

Khloe Kardashian, 32, is expecting a baby with boyfriend Tristan Thompson, 25, and she's planning to move to Cleveland to be closer to man during the pregnancy, a source tells X17online exclusively!

    "Khloe is SO happy. The pregnancy came as a surprise, particularly since Tristan's ex-girlfriend is currently pregnant, but Khloe got on board with the idea of having a baby pretty quickly."

We caught the reality star arriving back in LA this morning, wearing an oversized sweatshirt (to hide the beginnings of a baby bump?).

And get this -- her NBA star beau plans on flying into town this weekend to ask Kris Jenner for Khloe's hand in marriage! True to form, though, the momager knows all about the plan and has already purchased a Range Rover for Thompson as a "welcome to the family" gift. Our source tells us: "Khloe and Kris want everything done correctly. They don't want this to look like an accident and Khloe really wants to show the world that Tristan is her man. She wants to kind of follow tradition and have Tristan ask her mom for permission to propose, in hopes of making the engagement look more traditional and formal."

So regarding everything being done in the right order ... Tristan DOES have another baby on the way with ex-girlfriend Jordan Craig. He dropped her for Khloe and now Jordy's just had her baby shower and is about to give birth, right as Khloe's going to try to make her good news the headline ...