In a way, Olivia Hind had the ideal pregnancy: no morning sickness, minor weight gain and no stress. But then, she never knew she was pregnant

Some women are radiant during pregnancy; others suffer morning sickness and feel tired all the time. But for Olivia Hind neither was the case. She didn't even know she was pregnant until three hours before giving birth.

Cradling 16-week-old Madeleine in her arms, Olivia, 24, recalled the nine months she was, as it now turns out, pregnant. Looking back, there really were very few tell-tale signs. Once she was sick at the sight of a pizza at supper, but she put that down to food poisoning; another time her ankles swelled up but, given that she was waitressing six days a week, there was a plausible explanation for this, too.

She never felt the baby kicking and she lost rather than gained weight during part of the pregnancy. She never missed her monthly bleed and mistook her contractions for heavy period pains. It was only when the doctor said: "That's either a very large cyst or a baby's head," that the penny dropped. By then she was four centimetres dilated.

"I genuinely had no idea," she said. "Sometimes I think: 'How could I not have known? Did I feel her kicking?' But there was nothing. I even sat and watched a programme with my mum about exactly this happening to women. I remember saying: 'They must be either stupid or fat.' I didn't realise it then, but I was six months pregnant."

Olivia herself is neither stupid nor fat. She left university last summer and weighs eight-and-three-quarter stone. Even when she was full-term she only went up to nine-and-a-half stone. She was a little plump round the middle, but there was no bump.

Madeleine, who is nicknamed Maddie Madras because Olivia went out for a curry the week she went into labour, was born on Sunday 28 November weighing five pounds 11 ounces. On the Tuesday Olivia had felt lethargic at the gym, but had pushed herself with the weights. She had recently bought some new clothes and was keen to fit into them.

On the Wednesday night she went out for a curry with friends. By 4am she was doubled up in pain, but she put this down to the fact that her period was due. She took Thursday off work because she was feeling ill. She went to a physiotherapist near her home in Cobham, Surrey, because she thought she had a trapped nerve in her back carrying so many plates. "I stripped off to my bra for the physio and she didn't notice anything," she said. "I lay on my tummy and had my back prodded." Still nobody clicked.

The next day Olivia felt better. That evening she went out for dinner with friends and went to work on Saturday. But after an hour she told her boss she had to go home. She was feeling awful. At midday she phoned the doctor who said: "It sounds like you've had a bad case of food poisoning. If you're still feeling bad on Monday come in and have some tests." Her sister, Nina, 26, who came to visit in the afternoon, even joked that her stomach cramps might mean she was going into labour. Olivia cancelled going to London for a friend's birthday in the evening. By 2am on Sunday she had taken a turn for the worse. Her parents, with whom she lives, had gone for a week's skiing in Austria so she was alone in the house. "I thought maybe something had exploded and that perhaps it was appendicitis," she said. "The doctor came round and said it sounded as if I was having a miscarriage. I said: 'That's impossible'. We worked out that, if I was, it would be full-term. She lay me on the sofa and did an internal examination." Olivia did not know it, but her world was about to be turned upside down.

"Pack an overnight bag. I think we had better get you to the hospital," said the doctor. Olivia complained of another spasm. "That's a contraction," the doctor explained. Nina, who was back in London, might not make it in time for the birth, the doctor explained. "That's when it hit home," said Olivia. "It's one thing to say: 'That's a baby's head' and quite another to say: 'I think you're about to go into labour and give birth'."

While waiting for the ambulance, Olivia rang a friend, Juliet, 23, whose first reaction was: "Why didn't you tell us?" She then suggested: "Get in a taxi and come round. We'll have a bottle of wine and discuss this." Olivia explained that that was not appropriate.

Once in the ward, she heard Juliet and another friend, Amy, 23, teetering down the corridor in their high heels. They had come straight from a party. "It was strange because I felt very calm and relaxed," said Olivia. "Having Juliet and Amy there quite drunk made it more palatable." The only problem was that they kept borrowing the gas and air.

The doctors strapped a monitor to Olivia's stomach, pulling the straps very tight because she was not the size of an average full-term mother. "I heard the heartbeat which was amazing, but I didn't honestly believe I was going to give birth until I felt I needed to push," said Olivia. "One of the midwives told me what to do, but she didn't panic me with lots of information. She said: 'We'll cross each bridge when we come to it'."

Maddie was born at 5.32am. In hindsight Olivia is glad she was spared all the anticipation because there was no scope for anti-climax. "I had no expectations," she said. "I hadn't had nine months dreaming of this little bundle of joy. I didn't have to worry about whether it was a boy or a girl. At one point Juliet and Amy asked me what sex I wanted. I said: 'Four hours ago it would have been: 'which shoes are you going to wear'. I hadn't had images of leaving hospital feeling elated and wonderful. As a result, nothing was disappointing."

Olivia's instincts took over as soon as she was handed Maddie. "One minute you're you and the next you're a mother," she said. "I stuck my finger in her mouth and she started to suckle on it. It was the most wonderful, amazing feeling."

She describes Maddie as "a little miracle baby". "I couldn't honestly say I know what I would have done if I'd known," she said.

"It's a very difficult question to answer, but I wouldn't change it for the world."