Gaynor Rzepka was at work at the Filco supermarket in Cowbridge, Wales, when she began experiencing stomach pains. Returning to her parent's house that evening after a ten hour shift, she woke up at 1am with sharp pains in her side.
'The only way I can describe it is that it was like someone stabbing me in the right hand side of my groin.'
'I didn't think much of it. At about 5am I felt like I needed the toilet but couldn't go.'
'I had another sharp pain at about 5.20am and went to the toilet again. I stood up because I didn't feel right.'
'I just pushed and he arrived. I caught him before he went into the toilet.'
Rzepka said she had put on about a stone since Christmas and suddenly craved Mars bars, but other than than had no symptoms of pregnancy.
She said when the baby boy arrived, who she has named Olly-James, she burst into tears and sat down on the floor, unable to believe what had happened.
'My mum said: "It's a baby" and my dad was sayingL "Don't worry, keep calm."
'I just pushed and he arrived. I caught him before he went into the toilet.'
Miss Rzepka's partner Paul, who is a 29-year-old bar manager, was apparently 'over the moon' about the surprise news.
Gaynor had been lifting 25 kilo boxes up until a few days before she had the baby, and ran a marathon when she was unknowingly 5 months pregnant.
Her mother Tania, 53, said when she saw the baby her maternal instinct kicked in, and she helped to wrap up the baby and look after her daughter.