I say this as someone who was happily childfree till 40, with a partner who was equally committed to not having children, OP, so don’t think I’m coming out with the frankly insulting ‘not having children is weird/selfish’, ‘you’ll be lonely when you’re old’ stuff I got from parents from time to time. (Though never from actual friends.)
But what strikes me in your posts is that these are not dimwitted randoms at all party, but friends who presumably know and love you, AND, more importantly, that you say that these conversations have often made you doubt your decision, AND that you acknowledge yourself that you would be open to children in another relationship. Other people’s opinions never made me doubt my position.
I’m not saying there’s anything you necessarily need to do here, as, as pps have said, you won’t be having children anyway, in this relationship, as your DH doesn’t want them. Just maybe think about whether this decision is absolutely your own decision that you’re happy with.
If that is the case, own it, and tell your friends to kindly fuck off.
We don’t know these people, OP. Only you can tell whether these are nosy, interfering comments from the school of ‘Only selfish weirdos don’t have children by choice’ or whether these are concerned, perceptive friends who see that you’re not in fact certain this is what you want and are being a bit tactless and boundary-disrespecting in their way of approaching it.
Ultimately, you know you own mind best. Obviously.
Also, as a longtime childfree person with a longtime childfree partner, who eventually had a child together (now a teenager), the decision to ttc was very much a joint one, and while we’re delighted to have had our DS, I’m certain we would have had an equally, differently happy life had we not had him.