Kourtney Kardashian and Scott Disick
09/06/2009 AT 01:00 PM EDT
Kourtney Kardashian is about six months along in her pregnancy
, and the reality TV star's boyfriend, entrepeneur Scott Disick, has adjusted well to her mood swings, which are par for the course of expecting, she says.
"Scott keeps getting scared," Kardashian tells PEOPLE, laughing. "But he's been great with my mood swings so far. He's like, 'Just take a deep breath.' He heard that with the last three months [of a pregnancy] you really have mood swings so he was joking, 'Oh, you're not going to believe the mood swings!"
But the Kourtney & Khloe Take Miami
star, 30, has everything under control. "If I'm just trying to pick a fight with someone and if I'm around Scott or my mom, then they'll probably get it worst," she says. "If someone is annoying me – usually my mom! – I'll call [my sister] Khloe and it'll make me feel better because she'll agree with me."
As Kardashian's Christmastime due date approaches, emotional rollercoaster and all, so does the impending news of the sex of her and Disick's baby. "I'll know soon," she says excitedly.
Apart from being naturally curious, there's a practical reason to knowing whether she'll have a boy or a girl in light of the baby gifts she's started to receive: "How many yellow outfits do I need?" she says.