Medium pregnant with my first child and turning up nervously on a Tuesday evening to my first antenatal class, I was reminded of something by the circle of chairs, the sudden intimacy with strangers and the Jammie Dodgers. I had been here before, spending my evenings in church halls drinking tea from chipped mugs, talking about sleepless nights and shitting yourself: at Alcoholics Anonymous (AA) meetings.

I’ve attended hundreds of AA groups, mostly in the first year or two after I stopped drinking, and on and off for years before that. I know how it is to be rattled and raw and facing something unknown. Back then, I wondered what life was going to look like without constantly being trolleyed; now I’m facing it with a small person to be responsible for. And as with the rehab I went to, when I see all these people at turning points in their lives with different stories about how they got here, as a writer I think: this is great material.

In both groups, we measure time obsessively. I can tell you exactly how pregnant I am (29 weeks and six days) just as, for the first year or two, I knew how many days it had been since I had a drink. My group comprises six pregnant women – who will get bigger at each weekly meeting, like a reverse Weight Watchers – plus our “birth partners” – somewhat stunned men. As we go around the circle and introduce ourselves, everyone has got a due date, just as in my rehab we all repeated our sobriety date at each intense session of group therapy.

I have often thought that the 12-step programme for recovering from addiction, with its requirement of making a “fearless moral inventory of yourself”, would be useful for anyone, not just alcoholics. Here we are lucky to talk about our feelings and fears and motivations in a way that most people do not have the opportunity, without small talk. Just as you can share with a fellow recovering addict that you are aching, jonesing, you can answer a fellow preggo’s “How are you?” with “Exhausted, with heartburn and crying for non-specific reasons.” My first message to the “NCT girls” WhatsApp group concerned constipation.

Here, expectant first-time parents meet others so we can all share our inexperience, the blind leading the blind, to negotiate the consumer choices and clashing ideologies. Do I need to learn about hypnobirthing? To buy a nursing chair? Just what am I going to do with all these muslin cloths? Topics covered over the weeks include breastfeeding, what to do with a placenta, choices about pain relief, caesarean sections. There is a similar level of gore and drugs to a 12-step meeting, led by a teacher who has been there, like AA old-timers, wise and funny. I learn lots about the importance and roles of various hormones in childbirth. We all agree on the benefits of a “natural delivery”, under electric lights, via the internet. It is interesting and ridiculous.

One Tuesday night, we try out potential positions for labour. I’m balancing on an inflatable fitness ball with my boyfriend massaging my back, feeling silly, fat and happy, and sometimes there are just these moments where I think about how far I have come. I remember the cravings and loneliness of early sobriety, the heartache and romantic disappointments, and then the queasy holiday in Thailand where I thought I had contracted a tropical disease and did not realise for some time that it was, in fact, a baby. And now appreciate this everyday miracle happening inside me.

If I had not got sober, I would certainly not be in the position I am now, with the capability and resources to have a relationship, to have a child, to pay for a course of antenatal classes, to turn up on a Saturday morning to talk about breast pumps. When I stopped drinking, more than six years ago now, I knew that I had saved my life (I was on the trajectory of addiction towards incarceration, institutions or death), which led me to the question of what I had saved my life for – what was it I really wanted to do? I realised there were two big ones: write a book and have a baby. I actually used to visualise these things in the early days when I was struggling.

The truth is that most addicts do not get clean. I feel as if I only managed it by the skin of my teeth despite having a huge amount on my side: support of family and friends, youth, an education. Most people I met in rehab did not make it to the end of the 12-week programme and most newcomers to AA don’t stick at it. It is bloody hard. They have complex problems and traumatic pasts and a bit of my heart is with them all the time. But I got out and here I am six years later, with an aching back, sapped energy and constant slight nausea, discussing cracked nipples with a bunch of strangers in the basement of a Catholic church, and I couldn’t be more pleased.