Calculating backwards

My birthday is in five weeks and I have started doing the thing where I calculate backwards from forty. If we started trying in the spring. If it took a year, which it does for a lot of people and more than people say. If we wanted two, and the gap between them was what Hannah's gap was. I did this at a red light on Merrimon this evening with the indicator going and then felt completely insane about it for the rest of the drive. The clinical part of my brain knows that thirty four is not a cliff, that the numbers people quote at women are mostly population statistics badly applied to individuals, and that anxiety loves a spreadsheet because a spreadsheet feels like control. I have said versions of that to clients. I believe it. And none of that touches the arithmetic, because the arithmetic is not actually about fertility. The arithmetic is a way of asking how long I am prepared to wait for somebody else to be ready, and dressing it up as biology so it sounds like a fact instead of a boundary. That last sentence took me about ten minutes to write and I nearly deleted it twice.