Then I look down and everything falls apart.

The dots of blood on the toilet roll are like tiny bullet holes.

I freeze.

No. Not this time. Because if it’s over this time, there won’t be a next time.

Every step I take back to the bedroom feels perilous. Bear snuggles into me, and I decide to stay horizontal for as long as I can. Even though I know, logically, it will make no difference.

I can’t hold back the Bad Thoughts. Whatever the spotting means – that I am not pregnant, or that I was but am no longer – I realize that if I’d only kept my secret for a few more days I might have hung on to Dan.

And now, a worse thought: what if my confusion caused this, by sending a message to the embryo that I didn’t want it to implant after all?

I could call the clinic about the bleed. Except they’ll say, You must wait; everyone is different, it doesn’t mean anything. Unless there’s something specific you’re worried about?

What would I say? Funny you should mention it, but I’m worried my mental infidelity to my late husband has interfered with implantation.

Oh shit, I’m so scared.

There’s something in The Amazing Book of Us about fear, but I’m too scared even to go into the living room to fetch it. So I try to remember the gist of Andrew’s message: that you have to embrace fear, because it’s often a sign of good change. That fear and risk are worth it for the benefits they can bring.

But if he was here right now, I’d be arguing the opposite. That there is a limit to how much fear and pain we can take. That sometimes staying safe and hiding from the world is the only option.

When Bear begins to squirm, I know I need to take him out. Tentatively I get up again and, when I go to the loo, there’s no more spotting. But I can’t be sure if that means everything’s OK.

‘Let’s brave the outside world, Bear.’

We go onto the patch of green outside the flat, and he has the longest wee I’ve ever seen, then does a Downward Dog stretch on the soft, warm grass. But he stays close to me, not pulling or showing any interest in the sun-drunk squirrels that run across his path.

A couple with a buggy walk past, the baby hidden by a cotton zebra-striped comforter. The stab of envy takes me by surprise.

I make myself keep going, one slow step after another. I have only four days left to wait. Four days till I get a glimpse of what my future holds. As I picture those binary possibilities – P/not P – I can’t predict how I will feel.

Every gain comes with a loss. Every choice means choosing not to do the other thing.

I watch my dog as he sniffs delightedly, unable to resist following a new trail, totally lost in the moment. No worries for him about the road not taken. If there’s one thing I could learn from Bear, it’s that.