I had a baby at 33, then didn't try to conceive again until I was 42, when I fell pregnant naturally quickly (within 3 months of trying). I really can't explain it but I somehow knew my body was ready to be pregnant, both times. I have a coil now, and tell DH that I would have been one of those women having a baby every year in the olden days, I just feel i know when I'm fertile. Is that even possible? Or maybe it's the confidence and feeling relaxed about it, that helps.
I made a decision NOT to obsess about a second baby due to my age but as soon as DH agreed, I was desperate for a baby. It is so hard not to want it.
My pregnancy felt like harder work than my first I guess due to age, but uneventful. I was consultant-led due to my age, but the consultant agreed I was as low-risk as a geriatric mum-to-be could be, so she saw me once (to recommend an induction at 39 weeks, just on principle) but then forgot about me. Forgot to book my induction, which suited me fine! At 38 weeks I phoned up to check what I should do, and they promised to book the induction... but things got busy...so in the end I was induced at about 40 weeks. That went really well, compared to my first baby (also induced) - I did hypnobirthing and got through on 2 paracetamol and some gas and air.
I know that's pretty unusual as birth stories in your 40s go. But I share the story because it IS possible. I'm 45 now and actually quite frightened I could be pregnant if I wasnt careful. I check that Mirena coil is still there, quite often.
I made sure that in the run up to getting pregnant I was very, very healthy - swimming at least twice a week, brisk walking frequently, doing heavy gardening a lot to build strength and flexibility; also eating very healthily (cut out processed foods and caffeinated drinks, drank loads of water, increased whole foods, dairy, protein, etc). And took a prenatal vitamin supplement. I'm not sure these steps helped me get pregnant, but I know they made pregnancy and childbirth easier.
I do remember my first trimester being overshadowed by a gripping fear of the baby having a developmental problem, but scans were fine and I relaxed in trimester 2 and 3.
Now - I've got a toddler and a FT job again age 45, which is really hard work! But I absolutely love it. If I didnt have my second baby, life would have been very different, but I like to think I'd have dealt with the grief and made the best of what I have like I have had to deal with other sad things in my life.
Good luck Op.