@TedMullins because at the time they decided to sacrifice motherhood for men who SAID they NEVER wanted children they genuinely believed those men would stay in the relationships and not sod off after their fertility was basically non existent to enter new relationships and quickly get the new woman pregnant less than a year after splitting from my friends in both cases. It's a shitty thing that some men do unfortunately which is why yes women need to decide for themselves on this.
I had a strong (and correct as it turned out) that the path to motherhood for me was not going to be an easy one. My first pregnancy ironically was unplanned at age 18, getting pregnant apparently not the problem (even on the pill) staying pregnant was another matter. This was also my first mc. When I met my ex (after this happened) I made clear to him from the start that marriage and children were key for me and I wasn't interested in wasting my time. He wobbled a little at first (we were only 19/20 when we met) but I explained my reasoning and he understood. We dated for a couple years, he then proposed, we married within the year, he was honest that he wanted us to have 1st couple years married just the two of us and then we planned to ttc. A series of obstacles got in the way, mainly my health but also his job (army - kinda hard to ttc when he's 1000's of miles away 
) and on one occasion his health (tropical infection acquired while on deployment knocked him sideways) so that in all it took us nearly 5 years to get dd.
I do have one friend also who was adamant she never wanted dc to the point of ending relationships and trying to get sterilised (this is ridiculously hard for women in this country especially for those who haven't had a child), she then was involved in an accident that left her with an infection that eventually resulted in an emergency hysterectomy. She found it really tough to come to terms with despite always being adamant she didn't want dc. The fact the choice was taken away from her in an unforeseen way made her wobble for a while. Once she recovered and was doing better health wise and yes time is probably a factor too, she was fine with it.
Sometimes as a woman approaches menopause stage (either physically or mentally) they can second guess themselves on this a bit if they've chosen to be child free or I've even seen it with women who have children and they wonder if they want one more. One friend succumbed to this and while she loves her child wholeheartedly she does regret doing it at that age/stage for a number of reasons. Hormones can be utter buggers! Mess with your head!
Also bear in mind op even if you were able to get pregnant fairly easily, carry to term and deliver a healthy baby you're still going to be at least 58/59 when they reach adulthood and the stress does not end there! My dd is 20 and I'm very much still parenting albeit "remotely"
It's entirely possible that the main reasons you're considering having dc but don't really want them are:
Hormones - seriously they go nuts at this time! As I think I said upthread another pregnancy for me would very likely be fatal yet around this time I had just started seeing someone and was seriously considering the possibility - nuts!!
Socialisation - it's drummed into us from we're bloody toddlers that the "normal" thing is to want to be a mum! Boys and men don't have anything LIKE the same pressure socially/politically! It's everywhere! Embedded in our culture. My friends that chose to be child free by choice had a LOT of criticism - even from complete bloody strangers! I also once worked with a woman in the 90's and she would have been her late 50's then, she knew I was non judgmental on the matter from previous conversations about others and she confided in me that she and her husband never wanted dc, they had a small holding and were perfectly happy with their family of animals (not farmers they rescued various animals of all kinds and cared for them until they died naturally). They knew there'd be comments etc and there were plus pressure from both sets of parents so they decided early on in their marriage (this would have been in the late 60's) that it was just easier to lie/fudge and give the impression they couldn't rather than wouldn't. I know that some will disagree with that but I understood. Not ideal but I know at that time it was hugely taboo to be married and CHOOSE not to have dc. I'm the result of an unplanned pregnancy myself which led to a shotgun wedding to an abusive man! I think it would have been much better for all concerned had my mother not become pregnant by my father. I genuinely believe that.
Something you could try is counselling BUT make sure to get yourself a counsellor who isn't biased either way - that could be hard.
Because I'm in my 50s and have seen this happen more times than I can count, even with 'great' marriages. It happens.
Yea since I reached around 45 I've seen it happening more and more around me in people around my age.
I have to be honest and say the thing that most concerns me is the possibility of your having a child with a man who doesn't want one. That would be a disaster for everyone involved I think.
For you as you would be expected to bear the greater weight of responsibility and parenting I think especially the early stage tough parts (sleepless night, endless rocking/walking a colicky baby, teething) but also the later more onerous parts of parenting.
For dh being forced into fatherhood and living with a child (not just a baby but into adulthood) they never actively wanted
For the child being raised by an ambivalent mother and a quite possibly disinterested snd resentful father is a recipe for disaster.
It could well be a perfect storm for a buildup of resentment in at least one if not all 3 people involved.
Personally I think all children deserve wherever possible to be born wanted, loved and appreciated. I don't think that would be the case here.
Genuine question op have you much experience with children beyond the odd bit of babysitting sleeping ones as a teen maybe?
I'm the eldest sibling and cousin (both sides) and have been watching other peoples kids since I was 12/13, not just the usual teen babysitting, once I was 16 I was regularly hired to do overnight and breakfast care. Then from 18 all weekend or even occasionally full weeks (half terms etc) I then became a nanny and worked as a nanny for several years before entering nurse training. I nursed for a few years but found it wasn't for me. I'd also been a voluntary leader in various youth groups from the age of 18 too so had some experience with teens including residential settings and including working with teens who had not had the easiest start in life and that showed in various ways. I married my ex and had dd. So from my experience to that point I had a pretty good background of experience of babies and children of all ages. Nothing completely prepares you for parenthood (certainly there's nothing else like the early sleep deprivation it gives you!) but I think it did stop me from having a romanticised idea of what parenting is. I agree with pp upthread (sorry I've lost track of who) who said some go into it with rose coloured glasses on...and then get a rude awakening!
That was very true initially with one of my friends who was a teen mum, yes her youth was part of it, but also she was the youngest in her family and had never even done much babysitting or anything. She got a shock! Her parents were very supportive once over the initial shock and worry but they rightly still expected her to be the child's main carer. It was a very steep learning curve for her.
Another friend who is academically EXTREMELY intelligent but can be somewhat lacking on the common sense/street smarts side was an older mum in her late 30's. She was absolutely adamant baby would fit in with her and dh not the other way around. Even the fact that baby may not come exactly on due date threw her! She had it all planned to the nth degree inc going back to work full time 6 weeks post partum. She completely didn't understand how she would feel at that point - sleep deprivation, attachment hormones, lack of confidence etc she pushed forward with these plans trying to ignore how she felt and fell apart on that first day back at work, just lost it completely! Luckily she had an understanding boss who kinda expected this to happen and had made a contingency plan accordingly. She was completely unprepared for just NEEDING to be with her child.
Last time I checked the divorce rate was still 1/4
I think it's closer to 50% isn't it? Just checked 42% and those stats don't include cohabiting couples who've separated but I know cohabiting couples are more likely to separate 62% separation rate for cohabiting couples apparently
Not everyone should be a parent
Totally agree