I don't go back to the office but instead drive to Hyde Park. I park and then walk. And walk. And walk. Stopping only to barf and retch unproductively en route. It's an icy cold January afternoon. There's hardly a soul around, unlike the summer when the park is heaving with revellers. The occasional tramp shuffles by, and I see the odd figure dashing through the twilight, probably clerks who religiously office at five. Not paid enough, or motivated at all, to stay a minute after clocking-out time. Oblivious to their surroundings, they don't glance left or right - the park is simply something that must be passed through on the way heated rooms and hot cups of tea. The odd mother rushes by with her toddler in a pushchair. The kids are invariably ugly, tired and dirty. The mothers are all that, and also harassed. I suppose that pushchairs, previously beneath my notice, will soon become significant to me.

Pushchairs and high chairs and baby baths and cots and nappies and it’s impossible. It's alien. It's wrong.

Where is the unquashable exhilaration that, surely, should be the order of the day?

I’d settle for a faint flush of enthusiasm.

I walk on. I walk past the Serpentine, the desolate, deserted bandstand and around the Round Pond. I walk up and down. I circle. I walk so much that I'm actually warm even though it’s freezing and late. My feet and legs ache. I'm starving. And I feel sick. How's that possible? On balance the hunger is more compelling than the nausea. I'm so desperate that, for the first time since I gave up watching Black Beauty, I buy a hot dog from a suspiciously filthy man pushing an off-white cart. The cart, man and hot dog would fail all health and hygiene regulations with spectacular success. I try not to think about it. He piles greasy onions into the bread bun and then smothers the hot dog with mustard and ketchup which squelches on to his fingers and down his arm. He wipes his dirty hands on his dusty trousers, runs his hand through his hair and, the final flourish, wipes the back of his hand over his mouth. I don't care. The hot dog looks delicious. I'm that hungry I would eat the man, dusty trousers and all, if necessary.

Without even stopping to check if anyone can see me I gobble down the hot dog in approximately three bites. For about seven seconds I feel almost normal. My hunger is satiated and I don't feel sick, an exceptional state of affairs for the last month or so. On the eighth second my stomach lurches uncontrollably and I am hoying for Europe. The undigested hot dog, with onions, mustard, ketchup and trouser dust lies forlornly on the pavement. It's accompanied by two digestive biscuits, and I think that other thing is rye bread from my sandwiches at lunchtime.

'Ya fackin stupid bitch,' says the hot dog seller. What the fack did ya do that for? That ain't good for business, is it?'

I scrabble in my handbag and locate some tissues which I wipe my mouth, sick-splattered trousers and then I walk away, too weary to fling back a clever retort never mind reapply lipstick. I walk around the park again until I'm convinced that my boots are worn through. Finally, I throw myself on to the nearest park bench, not bothering about the bird excrement or chewing gum.

The park seems joyless. Littered with filthy vendors, rushing faceless people, dog muck and broken glass bottles.

I am growing a baby.

There is a baby inside of my stomach. Or womb, or uterus or somewhere.

I try to think about that for a moment.

And can't.

It’s so big. The thing, it ... he or she is probably about size of a single grain of couscous, but the fact that I'm pregnant is big. Too big.

Do I want to be pregnant? Do I want a baby (the natural conclusion)? I have no idea. My mind is completely blank. I rummage around a bit but there is only space, a yawning gap, a brilliant, dazzling, gleaming, glossy whiteness where a reaction or a response should be.

What will Hugh think? What will Hugh say?

Oh God.

I pull out my mobile and flick through the menu. Who to call? Hugh? God no. No. Not until I'm calmer, more certain. Of what? Certain of what to say, of how I feel. The idea of calling Drew, Karl, Brett or Julia, the people I work with, the people I've spent upwards of ten hours a day with, five days a week, for several years, makes me laugh, or at least it would if I didn't feel so much like crying. Whilst each of them is certainly sexually active, alert, even aggressive, I don't think any of them have ever connected the thing they do every Friday and Saturday night with making babies. In fact the primary concern has always been making sure sex didn't have anything to do with making babies. Sam? No point. Not unless I can somehow spin my pregnancy story so as to relate to finding her an eligible bachelor; she talks of nothing else. I dismiss a dozen or so other names, acquaintances that will trill that this is marvellous news. The thought terrifies me because I'm not certain that I'm ready to hear that.

Because I'm not certain it is.

There’s Jessica, of course. She is my mother. Albeit the type of mother who insists I call her by her Christian name, as she hates to admit that she has a thirty-two-year-old daughter and she hyperventilates if I reveal our relationship in public. She is so much the epitome of a ‘lady who lunches’ that my father ought to have placed a copyright upon her when they married. She’s all suntan and surgery, diets and drama. Her life’s work is turning back the hands of time. To give credit where it’s due, she’s very successful in realizing this ambition. She looks about forty-five whereas she’s nearly twenty years older than that. My parents live in Cape Town in the winter. My father is a very silent man, more notable for the things he doesn’t say than for the things he does. He is a retired diplomat, a career that suited him; he finds that the skills he developed in his professional life are still extremely useful as he negotiates his way towards his fortieth year of marriage. And Jessica, for her part, is the perfect wife for a diplomat. She knows things like how to address a bishop or a lord, which flowers last the longest in hot weather, and how to write an utterly charming thank-you note. She is at all times extremely practical and clear-sighted. To date, her maternal advice has ranged from which sunblocks are indispensable to the recommendation of personal trainers; I figure it’s time to use my joker card.

‘Darling, how lovely to hear from you. Oh God, it’s not your birthday is it? Have I forgotten your birthday?’

‘No, Jessica.’

‘No. Of course not. You were a summer baby. It’s not mine, is it?’

Jessica hasn’t celebrated a birthday since I was eight. Instead, she goes into a darkened room on the actual day and wears black for a week.

‘So why the call?’ A sad but fair testament of our mother-daughter relationship.

I consider talking about the weather but realize it’s pointless. ‘I’m pregnant.’

There’s a wail of horror. 'Oh darling. How could you do this to me? That will make me a - oh God I'm going to sit down – a grandmother.’ She hiss-whispers the last word, as though articulating a curse.

‘I didn't do this to you.' I splutter, resisting the urge to scream 'Bugger you, what about me?!’

‘I’ve been been dreading this call since you were fourteen. Oh darling. You didn't plan this, did you?' She's incredulous. We are, in many ways, very similar.

'No.'

'Is it Hugh's?'

'Of course.' I try to sound offended.

‘Well, that’s something, I suppose,’ she mutters. ‘It will, at least, be good-looking.’ This is typical of my mother. Untouched by traditional concerns, such as the facts that the child is unplanned, illegitimate and fathered by a married man, she focuses her attention on the aesthetics. I don’t know why I was expecting her to be supportive or cheering.