"Char had researched through the night and thought she had kidney stones," he said.
When the pregnancy test came back positive the couple were overjoyed.
"I was over the moon. My first reaction was shock.
"You get a bit confused. Am I actually in a dream?" he said.
He said his partner hadn't showed any pregnancy symptoms.
"She didn't have any morning sickness.
"She gained a bit of weight but she hadn't been out biking like she normally does," he said.
However the proud new dad said the shock was wearing off.
"It's the best early Christmas present.
"Carlo is perfect," he gushed.
He said although the couple weren't planning on having children: "it was the best thing that's happened to us".
The couple have been overwhelmed by the support from their friends, family and the Nelson community.
"We've had people show up on our doorsteps, even strangers, who are offering to buy nappies, and clothing."
"We're very very thankful. It's a massive massive weight taken off our shoulders," he said.
Mr Parkes said the local community Facebook pages were a great help.
"People have rallied around to get stuff for us," he said.
He said he was "blown away" when the couple started receiving international media attention.
However the attention wasn't all positive.
"Some people are saying how did she not know?
"At the end of the day people are going to show interest."
But the positive feedback outweighed the negative, Mr Parkes said.
Before the couple found out about the pregnancy, they were given 90 days to move out of their house as the landlord was planning to sell the property.
This worried Mr Parkes, especially with the new addition to their family.
"Things get so close to Christmas. I hope we can find a place in our price range."