Just to give a bit of background, I'm 40, with two kids already, wasn't planning anymore. Have some autoimmune diseases so not in the best of health, but I get by - live life at a slower pace than some, take my meds, etc. and all's fine (or fine enough for me, anyway). Recently got a job that I love, after 5 years as a SAHM. Then this morning I think, 'AF's late - better use up the pg test that's lurking about...' and it's positive.
How did that happen?! I'm on micronor (Pill) and, after a few early cock ups (as it were) I've been taking it properly, regularly, etc.
Anyway, that's not the real question. The real question is: in my shoes, what do you think you might do? Dh (who has retired to bed with a headache, brought on by the stress of worrying about it all day) is very much of the opinion that we should 'let nature take it's course'. To put that into perspective, one of the effects of my autoimmunity is that I have to take blood thinners to stay pregnant. By not doing anything, I will miscarry.
Thing is, despite seeing the sense of his suggestion, I can't quite bring myself to commit to that. Before dc1 I had 3 miscarriages and I don't want to go through that again. I know, I know - pregnancy, birth and another child will be 'going through' something else altogether. I know dh makes more sense but...ah...do you get me? 
Dh said this morning, 'Neither of us want any more children.' But ah, DH, it would now be more correct to say, 'Neither of us wanted any more children; one of us is now incubating a spark and feels slightly differently.
See - it's a 'spark' - it's a something - it's...there.
So, what would you do???