I'm 38 and a bit late for having kids too, plus the diagnosis of schizophrenia (and previous - undiagnosed - depression/bipolar-ish, OCD,...) and the meds I'm on could have teratogenic effect.
I used to want 4 kids at 19, but then worked with children and lost the wish
And as depression hit in, I felt I didn't want to impose this on any kids too.

Now that I 'can't/shouldn't' have kids I actually catch myself wistful at seeing other people and their kids.
I've worried about growing old without kids too.
I have a few child-free friends, and child-free forums have been a help in finding words for me and my relatives too. (My mum and dad used to want grandkids a lot, are slowly getting to terms that there probably won't be any...)

I don't want to physically have kids, wouldn't mind beeing a stepmom maybe, though I can hardly take care of myself, it seems. I'd like to have a partner/husband, ideally someone who can't have kids (anymore), not sure if birth control pills would be right for me, and some other methods aren't so 100%. So I stay single. Even though I'd prefer to be in a relationship. Ahh well... If I accidentally got pregnant I wouldn't get rid of the baby, but I would fear it would be 'damaged' in some way and not healthy...

In retrospect, I wish I would have kids when younger, when I still wanted them and was more 'gung ho' about things. But my parents fretted so much about me finishing education first and criticised my first boyfriend etc. I wish I had 'found someone' reliable and trustworthy earlier too - now I feel too old and 'damaged' (back/neck health etc).

I live with my parents and don't know what I'll do when they'll be gone, financially and otherwise. My ex classmates have almost-grown kids and I envy them a bit.