But her condition deteriorated that night, her husband was called and they went to Waikato Hospital.
Ten minutes after they arrived in the emergency department, Mrs Cameron's condition deteriorated further and doctors decided to deliver her baby.
"I had to go away and call the family and the first thing I saw when I came back in was my son on the table - this tiny little baby being resuscitated by four doctors - and that's when I started crying," he said.
"And then Nicky was laid out on the table. Her stomach was completely wide open. There were two guys with their hands right up her stomach into her chest cavity and they were resussing her and her body was just bouncing round while there were 20 people swarming round her, and there was blood all over the floor."
Mrs Cameron's heart had gone into cardiogenic shock, meaning it was unable to supply enough blood to the organs of the body.
Mr Cameron, a director of photography, said although he was terrified and overwhelmed, he was relieved to be able to see what was happening.
"This lovely nurse just stayed with me, she held my hand and told me what was going on. She said, 'Get in there, if you want to touch her face or hold her hand', but I was thinking, 'I'm going to be in the way'.
"Even in the midst of all that madness they were so kind and respectful to me," Mr Cameron said.
After 30 minutes, emergency nurse Jenny Wolfe stopped working on baby Billy. He had died.
But the race to save Mrs Cameron's life continued.
"I didn't think, having seen her, that she would pull through," Mrs Wolfe said. "But we just kept going; we had no choice as a team."
Having Mrs Cameron's parents and other family members in the hospital spurred the group on, as did knowing she had a son, Alfie, 4.
"It's very important that they see we're not giving up on her."
Dr Mark Goniszewski performed continuous CPR while another specialist held Mrs Cameron's aorta.
"To do CPR well is what saves a life and he did it very well," Mrs Wolfe said.
In her 10 years at Waikato Hospital she had seen only one other baby delivered during CPR.
"I've never seen a caesarean done so quickly. It was seconds and done under active CPR so we had both ends of the table running."
Dr Goniszewski said the team stopped intermittently to feel for Mrs Cameron's pulse, which was faint.
"We don't stop until everything's been ruled out. We give them a decent amount of time to correct what is wrong."
Finally, after 73 minutes and trying every medication and treatment they could think of, the team stabilised Mrs Cameron sufficiently for her to be taken into an operating theatre and then to the intensive care unit.
But Mrs Wolfe thought her patient would die overnight.
"I never expected her to live. I absolutely expected she would have had significant damage and never leave intensive care."
Mrs Cameron lapsed into a coma and the next day, the Westpac Waikato rescue helicopter flew her to Auckland City Hospital.
After a week, and on the day of her son Billy's funeral, Mrs Cameron opened her eyes, despite doctors preparing her family for the worst.
Knowing his wife was awake and that she recognised him made the funeral just bearable for Mr Cameron, who had named their son and planned the baby's farewell.
Mrs Cameron could not speak when she came out of the coma, but mouthed "baby" to her husband.
She was told Billy didn't survive.
"I tried to cry and I couldn't," she said. "I couldn't make the tears. I was so close to delivering. But I have cried a river of tears every day since."
She spent a month in hospital but apart from having a weakened heart, she has no other damage.
"It's a miracle. Thank God for the guy who didn't say at 60 minutes, 'Let's call it'. They worked on me even though there was a high possibility I would be brain damaged."
The couple are so grateful to their "superheroes" that they plan to meet the team at Waikato Hospital on Wednesday to say thank you.
