The post included a second photo that showed a close-up of the sonogram, surrounded by blue and white baby-themed cupcakes.
Speaking to TV Week, Josh couldn't help but gush over his unborn baby, and said that he couldn't wait to be a dad.
"There have been a lot of great things in my life, and some wonderful achievements, but none will come close to being a father and having a little man," he said.
Josh and Ashley went public with their relationship in December last year, after Josh posted a photo of Ashley holding their newly adopted puppy, Pippa.
"My two loves," he simply wrote.
Josh also shared an inside look of the two spending the Christmas holidays together last year, uploading two sweet photos of him and Ashley looking happier than ever.
It's unclear how long the two have been dating, and while Josh and Ashley have been fairly low key about their romance, it hasn't stopped the former AFL star from showing off his beautiful girlfriend.
"Hot baby mumma!!" he recently shared to social media, posing with Ashley as they both smile for the camera.
The couple will soon become a family of three, or four if you include their beloved dog, and look more than ready to be proud parents.
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