But admits keeping their special news under wraps has been tough.
“I was so paranoid,” she laughs.
“We attended an event at the end of November and I wore a dress which did nothing to hide my tiny bump. The next morning we woke up to a tonne of articles questioning whether I was pregnant. The last thing we wanted was to feel pressured into revealing the news too soon – especially after our last disappointment.”
And with the silly season in full swing, the mum-to-be reveals she and Matt were forced to trick family and friends.
“As soon as I fell pregnant, all the wedding and event invites started to arrive,” Byrne explains.
“I knew I’d have to keep a glass in my hand at all times but Matt would have to secretly swap glasses and drink it for me so no one would suspect anything. He’s had to endure some severe hangovers as a result.”
Byrne and Johnson, who have been dating for 18 months, met when Johnson starred as The Bachelor on Ten’s reality series in 2017. Byrne, 31, a jewellery designer, beat rival Elise Stacy in an emotional finale to win his heart.