Facebook just told me that four years ago today I stuck up a picture of this badge to tell my friends I was pregnant.

I can’t actually believe it was four years ago but it’s thrown into sharp relief the fact that most women in my situation would have had another baby by now. Or at least be pregnant.

Take my NCT class – of the six of us, all five of the others have had a second baby. I am the only one with only one. Just like I was the only one who didn’t manage to breastfeed, but that’s probably beside the point.

Or is it? Can we all find ways in which we feel like we don’t fit in, that we’ve wandered off the expected track, if we try hard enough? I don’t know if that’s the case, or if it’s just me overanalysing everything as usual, but I have always felt a little bit ‘different’ from my peers. And motherhood is just one of the ways in which I seem to have inadvertently not fitted in with the norm.

When my NCT friends started getting pregnant with their second children, I remember thinking ‘Shit, I better get on with it.’ Around this time people started asking if we wanted another, or, more rudely, ‘when are you going to have another?’ And I would sit there and stare at them and struggle to find a coherent answer. It wasn’t that I was against having another child, it was just that I wasn’t sure. The question felt huge, too big for me to find the answer.

“The decision to have a first baby, in my opinion, is pretty easy, because you have no idea what you’re letting yourself in for.”

Oli and I spoke about it a lot. Perhaps it would have been easier if he felt strongly either way, but like me, he was on the fence. We love being parents – we worship our daughter – but at the same time, neither of us feels any burning desire to have another child. If I had fallen pregnant unexpectedly we would have been scared but I’m sure we would have been delighted too. But making the conscious decision to have another child was another matter.

The decision to have a first baby, in my opinion, is pretty easy, because you have no idea what you’re letting yourself in for. But having a second is a whole different ballgame, because you know exactly what it will entail. And you have another small person to consider, who’s your whole world, and you know that whatever you do will impact them enormously.

So I did what I always do when faced with a question I don’t know the answer to: I researched it. Were only children really unhappy spoilt weirdos? Were children with siblings really much better adjusted? Was it really terribly lonely for children without siblings when they were older? How did it really affect relationships when you have two young children to look after? How much did siblings really play together and how much did they fight?

The results were fascinating, and (of course) subjective. But the overall message was that the perfect family size is the number of children you have, because if you love them they will be happy. That siblings are definitely not a guarantee of happiness, that (of course) nothing in life or relationships is as simple or clear cut as this, and that the most important thing is that your child grows up happy and well-adjusted with loving parents. No amount of brothers or sisters can compensate.

Oli and I are different parents in other ways too, of course. We are both self-employed, with unreliable and irregular incomes. Neither of us knows how our work lives will pan out. We are getting on a bit. Although I’m not too old to have a baby at 38, I’m not exactly a spring chicken. We have a comfortable, lovely life in a house that’s big enough for the three of us, but would be a bit of a squash if we had another. I’d like to be able to afford for Daphne to have piano lessons when she’s older, for us to go abroad once a year. Maybe I am wrong to be thinking of the practical considerations, but when practical things go awry it causes great stress, and stress affects everything.

A lot of people told me that they grew up with a very fixed idea of how big a family they wanted. They always wanted two kids. Or three. I never had that. I was never really that sure I even wanted one. I didn’t grow up dreaming of motherhood. Now that I am a mother, I feel unbelievably blessed, but I never had a fixed picture of what size and kind of family I wanted to be the matriarch of.

“I love our little family. I love it so much that I wake up in the night sometimes terrified that it’s all going to go wrong.”

And that’s the other thing. I feel unbelievably blessed. I’m risk averse. I love our little family. I love it so much that I wake up in the night sometimes terrified that it’s all going to go wrong. I’m so grateful to have our daughter. I feel like I’m tempting fate just writing this. What if we had a second child, and that second child had health problems, or my pregnancy went wrong? Or my inevitable exhaustion at having a young baby to care for affected my relationship with Daphne? Made me snappy and irritable with her? I had health issues with my first pregnancy and the stress was unimaginable. I just don’t want to put myself through that again. Which probably makes me a coward and a massive pessimist. I’m not sure, I’m just so grateful to have what I have, and there’s a voice in my head that continually shouts ‘don’t push your luck.’

So, we are probably not going to have another child. I have kept all Daphne’s baby things just in case I wake up one morning feeling desperate to procreate again, but my gut tells me it’s unlikely to happen. The thing that really clarified it was one of my friends asking me: ‘If it was normal to have one child, rather than two, would you be thinking of having another at all?’ And the answer was a resounding no. Which leads me to believe it’s the pressure to conform that’s the strongest voice in me contemplating having another baby. And that’s the worst reason of all.

It’s lonely though, being a mother of an only. Even though it’s becoming increasingly common, most of my friends with kids have two (at least). I feel like there should be some kind of support group for the ‘one and dones’. I find I am increasingly fascinated by modern motherhood and all its iterations. My novels focus on parenting in our contemporary world – my work in progress centres on a stay-at-home dad, and my upcoming book Unfollow Me is about an Instagram mum. I think the myriad different ways in which people parent in the 21st century are something to celebrate, not judge.

I hope this post doesn’t sound spoilt. There are, of course, no guarantees that I would fall pregnant again anyway. And as I said, I know how lucky I am. I really do. But I wanted to post this as an answer to all those people who keep asking me when we’re going to have another.

I also wanted to share my thoughts on this intensely personal and loaded subject, just in case there’s anyone else out there feeling a bit alone, as they go through the same thing.

You can find out more about THE RIVAL on my website, and order here if you want to make my day. UNFOLLOW ME will be published in June.