Juanita Stead, 36, was at a New Year's Eve party when the pain started and escalated to the point where her husband, Terry, took her to the hospital in the eastern town of Carbonear for X-rays, the Carbonear Compass reported.
"The technician looked at me and said, 'My dear, you're pregnant with a full-term baby.' And I said: 'No sir, you got the wrong woman and you're looking at the wrong screen. There is no way I'm pregnant,'" Stead told the newspaper.
She said her menstrual period hadn't stopped, there wasn't any morning sickness and she didn't put on extra weight.
Her other son also made an unexpected arrival on July 30, 2006, at the couple's home, Stead said. While she knew she was seven months pregnant, she was caught off guard.
"I felt like I had to go to the bathroom and out he popped, right into the toilet," she said. "Terry actually scooped him out of the toilet and put him in my lap until the ambulance came."