While the pregnancy came as a happy surprise, the couple have had to make some changes, especially in regards to their upcoming nuptials.
"We were looking at a few wedding venues, but then the pandemic and The Block happened, so we put it on hold, and shortly after that Olivia was pregnant!" Luke said.
"It would have been around this time that we were looking to get married, but we couldn't be happier."
The former Love Island Australia star first announced his engagement on Instagram last year with a sweet photo of him and Olivia diving in Byron Bay.
"Took this girl diving today and popped the question at the bottom of the ocean! Was a moment i will remember forever," he wrote at the time.
In the photo, you can see Olivia holding a sign that read: "OLIVIA JESSICA KISS. You make me the happiest man. WILL YOU MARRY ME?"
Now, the pair will be celebrating once more upon the arrival of their little girl, with future uncle Josh just as excited.
"I'm going to spoil her! I don't think I'll be a dad any time soon, so it'll be a bit like trial and error for me," Josh told Woman's Day.
"I'm really looking forward to it," he added.
And, if Luke's predications are anything to go by, Josh can expect more nieces and nephews to come.
"We're definitely going to have another and then we'll just see financially where we're at," Luke said. "If we can afford a third, I'd definitely like to have a third."
To find your own fairytale love story, sign up for eHarmony today!