The Die A Happy Man hitmaker's wife Lauren reveals they quietly filed adoption paperwork last year (16) after struggling to start a family of their own - only for the 27-year-old to conceive in late 2016.

"We tried to get pregnant for a little bit before," the mother-to-be tells People.com. "It was a good chunk of time and our family is extremely fertile, so I was expecting it to happen easily. I was like, 'Maybe this is the Lord's way of telling me adoption is what he wants me to do'. And I was OK with that."

Thomas and his wife, whose own mother was adopted, had no idea they were to become biological parents too until Lauren started feeling ill while on a Tanzania safari vacation with Florida Georgia Line star Tyler Hubbard and his spouse Hayley in December (16) .

"I was 100 per cent sure I was not pregnant," she recalls. "When we began the adoption process, we said, 'Let's wait, let's give this adopted child his or her time with us and then we'll continue our family'. So I was convinced it was food poisoning."

The news came as a huge surprise to the pair, which wed in 2012, and 26-year-old Thomas confesses, "I was in complete and utter shock! No one is ever prepared for something like that. It is almost like we suddenly had twins."

The unexpected double bundle of joy has left the couple feeling "more than blessed", and Thomas and Lauren are hoping to finalise their adoption soon, before their biological child is born in August (17).

The singer has started to collect parenting advice from his country star pals, and he's well aware sleeping will be their biggest issue.

"I've been doing as much talking to other artists who have kids as possible," he says. "I had dinner with Dierks Bentley and his wife the other night and I got a few tips from Dierks. He was like, 'Well, you're not going to get any sleep and Red Bull (energy drink) is going to be your best friend!'"

Thomas, who kicks off his latest live trek later this month (Feb17), has even started converting his tour bus into a more family-friendly vehicle so his family can stay with him when he heads out on the road, and despite the shock of Lauren's pregnancy, the couple "could not be happier".

She concludes, "We feel like 2017 is going to be our big year."