But as she enjoyed a romantic day on Miami beach with her on/off boyfriend Scott Disick, Kourtney kept her burgeoning belly under wraps with a huge stripy tunic.
As the 30-year-old theatre graduate joined Scott, 26, for a dip in the sea, the modest celebrity decided to keep her billowing top over her bikini.
Making waves: Kourtney Kardashian and boyfriend Scott Disick enjoy a cooling dip in the sea at Miami Beach on Sunday
The couple, who originally split in February before getting back together a few months ago, spent a lazy Sunday relaxing on the beach.
During the week, Kourtney and her younger sister Khloe, 25, have been running their new clothes boutique Dash, a Miami branch of their LA store of the same name.
Their business and partying exploits have been at the centre of a new reality TV show Khloe and Kourtney Take Miami, a spin-off of Keeping Up With The Kardashians, fronted by their more famous sister Kim, 28.
While the couple appeared in good spirits as they kissed and cuddled on sun loungers, Kourtney recently admitted to experiencing bad mood swings during her pregnancy.
Blooming: Modest Kourtney kept her burgeoning belly under wraps
Relaxing: Kourtney lays back and enjoys the sun
She told People magazine: 'Scott keeps getting scared. 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."'
Since announcing her baby news on August 12, Kourtney has been filling the US gossip magazines with every little detail of her pregnancy.
Kourtney, whose rocky relationship with Scott featured on Keeping Up With The Kardashians, admitted the pregnancy was unplanned, but the couple were excited about becoming parents.
Amorous: Scott lays a protective hand across Kourtney's stomach as he moves in for a kiss
Keeping abreast of things: Kourtney and Scott catch up on their reading
She said: 'This probably sounds so dumb, but there's so many times I'll forget to take my pill and I don't think it's that big of a deal. It's just so stupid.'
Kourtney said her famous family were thrilled when she told them she was expecting, but said her stepfather, former Olympian Bruce Jenner gave her a reality check.
She told Us magazine: 'He said, "You guys are acting like you're getting a little puppy dog! You need to take this seriously." He freaks me out the most.'
While the couple aren't sure the sex of the baby, Kourtney is hoping to have a natural birth.
She said: 'I used to think, "Oh, just get a C-section and it's done and easy and whatever," I've already changed since before being pregnant.'
Baby on board: Kourtney's bump was visible under her billowing top
