I’m afraid that I agree with the majority, and that’s despite doing something almost exactly the same. It worked for us, but we didn’t have such a short amount of time, we were much older, and so wanted to get on with it anyway, and we weren’t living close by. Despite this, i still, in hindsight think it was very rash.
At various points I’ve had miscarriages, pregnancy scares, been very unwell with pregnancy, and cannot imagine how I would’ve felt if that had been during that time. Meanwhile, there are so many ways in which it might not quite go the way you want, and any of it could feel even sadder. What if you find out your pg only a short while after your mum passes away? What if you don’t get pg at all in the next year? What if you do, but then there’s a big issue to deal with?
I know some of this has already been covered, and I’m probably being a bit stark, but you need to know, the chances of you “just” becoming pg, going full term, having the energy, fitness, and mental clarity to deal with all that is to come, is not 100%. The chances are that there will be some kind of hiccup at some point.
Talk to your mum, make plans, include her in your daydreams, take photos, listen to her reminiscences...and keep items and memories for your children to come.
I still have many many moments where I almost feel my breath is taken away by my wish that my DF had met my youngest, and seen both my children at 4,8,12...I am not sure that ever really goes away.
Anyway, sorry, too much, but I hope something among all that was helpful. 