Five-minute memoir: Natalie Lucas' parents decided to keep her on the basis of coin toss

'We said heads we keep it, tails we don’t.' I glare at my father. I want to cry

Did your mum never tell you this story?" I'm 16 and sitting at the dining table of the home I grew up in. Last week I stormed angrily out of my mum's house and across town to live with the father I've barely spoken to in four years. We have a lot of ground to make up, and this table, the microwaved rice and the defrosted curry between us are the terms of our armistice.

Tonight, my dad has drunk half a bottle of burgundy and somehow we're talking about times when my parents still spoke. I laughed a moment ago when he asked me to picture him at 29, his bald patch filled in with hair and his lip sporting a Tom Selleck moustache.

I've stopped laughing now, though. My dad has just told me he and my mum flipped a coin to decide whether to keep or abort me.

He pours himself another glass of wine.

"Maybe I shouldn't tell you."

"You have to now," I say seriously, digging my nails into my palm.

"OK then," he relents easily, warming to his anecdote, apparently oblivious to my anxiety. "Your mum and I were both working, both had careers in the city. I was doing up a house and she'd just bought her flat. We'd hang out at the weekends, meet friends at the pub once or twice a week."

I breathe through my nose and try to picture my parents young and childless; I fail.

"Your mum knocked on my door one day and I could see she was upset. She stood there on the doorstep and blurted something like: 'I'm pregnant and the doctor says I need to tell you before I can take care of it'."

My dad eyes me now, perhaps losing his nerve. I gaze back at him, arrange my mouth into a moderate smile. I already knew I was an accident and that my parents had only met a year before. I think back to my Philosophy and Ethics class's discussion about a woman's right to choose. Where, I wonder, was my mum when she found out? What was her first reaction?

"I said maybe we should talk about it," my dad continues. "So she came in and we sat down and tried to work out what to do. We couldn't, though. We talked and talked, deliberating for days. We even made a spreadsheet, trying to calculate if we could afford to have a child.

The answer was a resounding 'no'; babies are expensive. But then we looked at the spreadsheet and asked each other how, if two professionals on London salaries couldn't afford to have a child, anyone ever did? We threw out the spreadsheet and we were back to square one. We couldn't make a decision. There were as many arguments to have you as to not."

"So you flipped a coin!" I shout, unable to contain myself any longer. My anger echoes around the floorboarded house and my dad stares at me in surprise. Did he expect me to find this story funny?

"I'm sorry, sweetie, we didn't know what to do. We were talking ourselves in circles and growing more and more frustrated until one of us said, 'We might as well flip a coin'. It didn't seem absurd. We said heads we keep it, tails we don't."

I glare at my father, the word "it" reverberating in my brain. I want to cry but I don't want to do it in front of him.

"I pulled a penny from my pocket," my dad is still speaking, a smile playing at his lips again. "I asked your mum if she was sure. She nodded. So I threw it in the air."

I watch him catch the mime coin on the back of his right hand, cover it with his left. I clench my teeth.

"The thing is," my dad says, sniggering as he seeks eye contact. "I never looked!"

"Huh?" I exhale my anger into this one, inarticulate word.

"I never looked at the result. I told your mum it was heads, but I never checked."

A week later, when my mum and I have cooled from our fight, I tell her I know this story. She looks at me sadly, her eyes studying mine for signs of trauma. "Oh baby," she says, "I wish he hadn't told you." I can hear the pain in her voice, but I feel only my own. I assume she's upset that I know how close she came to getting rid of me. But what she says next completes my unlikely origins story and leaves me feeling both loved and lucky:

"It's true. We discussed it for days, deciding nothing. Eventually your dad said we might as well flip a coin. I agreed because in that time, I'd been carrying you around, feeling you inside me. We'd been talking to each other in the bath, you and I. By that time I knew, whatever your father decided with his spreadsheets or his coin, you were already my child."

'Sixteen Sixty One' by Natalie Lucas (The Friday Project, £7.99) is out now