Some things are planned, and others are not. The day after I book flights to go and see my parents in a few weeks' time, I find out I am pregnant. I have never been a planner, but out of all my pregnancies, this is the biggest surprise. I call R at work: "Guess what? I'm pregnant."

I don't go for a dramatic X Factor pause. The news is enough.

"Oh. Oh God," he says.

"It's fine. Well, it's not. But I know what I want to do and I think we should talk."

I cry, mainly because it's all a bit of a shock.

"Oh, right."

Now the pauses come into play, and I can sense that R really doesn't know what I want to do.

"I don't want another baby," I say.

"I think you're right, darling, but let's be sure. I'm in the middle of the office and I want us to talk about this, but it's hard now. Can I call you later? I love you," R says.

I go about my day like a very not-pregnant person, trying to pretend that I didn't see two blue lines instead of one on the pregnancy stick. But, of course, it is impossible. By the afternoon, with the children trying their best to distract me with their unfailing energy, I pick up the phone to the doctor.

I am given a number. I call a central booking line and speak to an incredibly helpful woman. I can't quite believe how easy it all is, and I am truly grateful. I am even given date options, which I somehow feel I don't deserve. When I'm asked for my age, I feel ridiculous admitting that I am in my 30s, have three children already, and should probably know better.

I am booked in to a local clinic in a fortnight's time.

R hasn't yet called back, but if we need longer to decide I can cancel or rearrange. I pray the nausea won't kick in before then, as I really have no idea how pregnant I am (my periods are very erratic).

I am cooking the children's supper, and look up from the hob and over to the calendar on the kitchen wall.

A very pleasing cross sits in a square, with the word HOLIDAY. I'm trying to work out a code word for TERMINATION so I can mark this on too.

Just thinking about it makes me feel careless and irresponsible, but most of all sad. The holiday date beyond the abortion is something to look forward to though, a plan with a purpose of nothing else but fun and togetherness.

R will not come with us: I asked him last week, but he says it will be hard to find cover at work. Really, though, we have usually taken our holidays apart. Up until the last minute, R always remained noncommittal, so either my breaks away were very low-key, or built around the fact that he could change his mind: but he never did. So we went, and R stayed at home, alone.

I know the main reason I have been reluctant to make plans in the past has been fear: if I left R at home for more than a night, then everything would suddenly fall apart.

It comes as a minor dent to the ego to realise that even if R goes on the most gargantuan binge, he will probably be fine without me.

The last family holiday we went on was five years ago and ended up with R booking himself back on the flight a week earlier than planned. I stayed on with the children and he went home.

At the time he had been flitting from abstemious to binge-drinker, but he was still in denial about his alcoholism. It was a tense time. He was withdrawn, uptight and often angry. All of the things you should not be when away from the stresses and routine of everyday life and work.

I remember him distinctly saying, just before he left: "I'm causing everyone grief here, and I'd be better off just going so you can enjoy yourselves." I was livid, because I felt any vitriol from me would be unwarranted: he was thinking about us. The coming holiday without R will give me a chance to enjoy my children's company, and put the past few crazy, unsettled weeks to bed.

And it will provide a necessary distraction after the abortion: I am almost certain that another baby is not what R and I want or need, but I'm not so sure that we won't feel grief. I can't help but think that if we were in a more stable relationship, another pregnancy would be something to celebrate.