New mum Gaynor had no idea she was expecting a baby, having put on just 13lbs in weight in the nine months she was pregnant.
The 25-year-old supermarket worker from South Wales had run a half marathon five months into her pregnancy and had even completed a 10-hour shift at work the day before she gave birth.
Gaynor said: "I didn't have any signs, no morning sickness, no pain, no heartburn, nothing at all. I had periods all the way through.
"I didn't really put on very much weight until Christmas, and I just thought that was a Christmas belly."
However, after waking up to a sharp pain in her side, Gaynor went to the toilet, where she gave birth to 6lbs 5oz Olly-James.
She said: "I was having a really sharp pain in the side of my stomach all day and I didn't know what it was..
"At about 5am I felt like I needed the toilet but I couldn't go. I had another really sharp pain at about 5.20am and went to the toilet again.
"I just pushed and he arrived. I caught him before he went into the toilet. I was really shocked."
Gaynor was at first scared of how her 29-year-old boyfriend, Paul Rawcliffe, would react but luckily, he was over the moon.