Listening to people who are already parents/mothers and have experience with academic professions is much more sensible and mature than ONLY listening to those who agree with you who aren't yet mothers themselves and don't have any knowledge of academic careers.
I had dd at 28 after 5 years of obstacles BUT I have endometriosis which although it was undx at the start of that 5 years, I had a long history of Gynae symptoms inc a mc at 18 (unplanned pregnancy) so I was genuinely concerned that I'd likely have difficulty conceiving, staying pregnant and birthing a healthy child - and I was right. I suffered 2 ovarian torsions and another mc which was partly ectopic (twins, this is incredibly rare) in this time and the endo was dx/found during the initial surgery for the mc, I had to have more surgeries+medical treatment bad careful monitoring in the year between that and getting pregnant with Dd, then was very carefully monitored while pregnant with dd, put on complete bed rest from 7 months then a traumatic and dangerous birth during which we both almost died then I was told I would literally be risking my life if I were EVER to become pregnant again. (Not the endo something else came up)
In addition I was working as a nanny and had a LOT of experience caring for babies and young children and knew the cons as well as the pros and even so also knew it would be even more exhausting and demanding when it was 24/7 - which tbh even with the most supportive and involved partner/spouse in the early years it really is utterly relentless!
Yes you can still have fun and do things with a child BUT it's a lot harder practically, more expensive and takes a LOT of organisation. It's hugely different to how things are before a child
I'd done a lot before having dd, uni, career stuff (I'd been a nurse), travelling, living abroad...
It doesn't sound as if you've done much at all especially as you've been in this committed relationship since you were...17.5?! Tbh that's crazy young to "settle down" you haven't even really experienced dating!
In my opinion you barely know who you are!
Plus people change a LOT in their 20's, not just emotionally but bio-physically speaking, neurologically we're still "teens" until around your age! I think that shows in you in your narrow focus on this one desire! It's a very teenage thought pattern and approach - the overgrown toddler attitude "this is what I want and I want it NOW" barely able to consider even slightly (and 2 years over a lifetime really IS slightly) delaying gratifying that desire.
You also seem (worryingly considering it's your stated career goal) very ill informed as to how academic careers work.
I have several friends who are lecturers/professors, college and university level and even before covid with all the cuts further and higher education was really struggling! Very very few have permanent posts for the first 5 or so years, they're effectively (as pps have said) zero hours contracts
To get a permanent post in this area you generally need at least a phd, a good publication history and several years experience. It certainly won't happen as soon as you attain a masters!
It's a very male dominated career still too unfortunately, and while legally they cannot be open about this, the reality is they're pretty poor on equality and maternity rights generally speaking. My friends in these jobs who are mothers, especially when the dc are very young (not the same for fathers quelle surprise!) have found they miss out on jobs, promotions etc again it's not overt discrimination but it's definitely there especially in the older unis.
Academia is demanding, exhausting and requires employees to put in crazy hours to have a chance of doing well - this is not generally very compatible with early motherhood.
In fact your attitude suggests to me you might even have thought this was a good job to go into as someone who wants to be a mother soon because you've only focused on contact time with the students and think you'll have a lot of free time and long holidays?
I've lived with (as flatmates/me as a lodger) teachers and lecturers and I can assure you that outside of classroom time they had a LOT of prep, marking and research to do.
To be perfectly honest if you're a secondary teacher now I'd have thought you'd have more insight there.
Take a step back, learn more about what it takes to become a lecturer, learn more about early motherhood and juggling such a career from those who have/are doing it and LISTEN to them, LISTEN to your fiance.
Another thing - marriage is all about compromise and you don't seem very good at that, your fiancé has perfectly good REASONS not excuses for not wanting to ttc right now. You need to think about why you are so resistant to considering that his feelings and thoughts are valid too? Is his job secure? Maybe that's something he's worried about? Very few jobs are in these strange cuts/covid/brexit times
Having a child is a HUGE life changing choice, it really should not be done lightly and without full consideration of all the physical, practical, health, financial and emotional ramifications.
2 years really is no time at all, and you can even use that time to:
Get as healthy as possible (both of you)
Save for the first few YEARS of baby's life because to be honest childcare alone can be very expensive - have you even looked into this in your locale?
Get your home ready
Figure out the career stuff PROPERLY - not this vague idealised notion you seem to have at the moment
And I bet the time would zip by!
Personally with everything that's going on at the moment I would totally understand anyone who's at child bearing stage/age being wary at the moment and possibly wanting to wait until:
We see how Brexit goes
There's a covid vaccine or covid wise things are MUCH more settled
At the very least,