Last time, I told everyone straight away. I was thrilled and saw no point in waiting for three months, by which point many people have guessed anyway. I knew that if I had an early miscarriage I would want to talk to friends, so it would be better if they knew I was pregnant.

But this time I don’t want to tell anyone. People smile and say things like, “You must be thrilled!” I can see some friends think my news means my life is back to normal, that this erases all the pain of the six months since my three-month-old son died of sudden infant death syndrome. But I’m not thrilled – I’m terrified, sad and grieving.

My last pregnancy was complication-free, so there’s no reason to think anything is likely to go wrong. But with each test and milestone I feel utterly vulnerable to fate and have little faith that the tiny spark of life inside me can pass unscathed. I check for blood with every toilet visit.

And then there’s the sadness. I’m sad this pregnancy won’t be one of happy anticipation. I’m sad this baby isn’t going to be the perfect son I lost. I’m sad that this saddens me – this baby is just as deserving of my joy as my last, and will be just as perfect, if all goes well. I cling desperately to the belief that when I see this newborn baby all the love that was there before, will be there again.

So when you hear our news, please don’t assume we are back to square one. We are on a different, much more difficult journey. And please don’t think we no longer need all the love and support you’ve given us. We will still need that for many months to come.

• Tell us what you’re really thinking at mind@theguardian.com