"Reality check when you are carrying twins.. you are rotund much earlier!! Felt like I was in a tight jacket all day.
"Not to mention everyone got a good look at my belly button (no longer an innie). Need to dress more appropriately," she added.
Fans were quick to praise the star for her gusto, with one commenting on the snap, "Jana, you are such an amazing person!! We recently watch you on SAS Aus and you blew our minds! Such a role model and inspiration. Take care."
Another added, "Are you a real person? You truly amaze me!! 😂"
The powerhouse former Olympian, athletics star, doctor and mum-of-four (soon to be six) recently opened up to New Idea about the struggles of being pregnant with twins while caring for her growing family.
“It's been hard, to say the least,” Jana exclusively told New Idea. “Just the fatigue, working full time, all the hormones and everything have been really rough.”
Jana, who currently has four kids, Charlie, one, daughters Emily, six, and Jemima, four, and Cornelis, 14, added that she realised just how different of an experience it is to be pregnant with twins.
“As a future obstetrician, hopefully, it's been a good example for me to see how difficult carrying multiple babies are, especially when you're approaching 40 years of age.”
WATCH: Jana Pittman shares her home workouts with kids during isolation
While juggling a household full of six kids may be daunting for some, Jana and her husband Paul Gatward can’t wait to expand their family, and the kids are just as eager to welcome their new siblings.
“They're over the moon - they think it's fantastic,” Jana said. “They constantly kiss my tummy and they're always trying to get involved and trying to name the kids.”
With the extension of her family in 2022, Jana saud it will be a “real challenge” ahead to try and balance her career with family, but she sees it as a “huge blessing”.
“Working in women's health, I see how many women struggle to fall pregnant,” she revealed. “So to be able to have the experience of carrying twins, but also being able to extend that family to such a big family is a real blessing.”