"Life is what happens while we're busy making other plans"
If you're of a religious persuasion
"If you want to make God laugh, tell him your plans"
I had dd at 28, had been married 6 years and we'd started trying for a family 5 years earlier. We were both in secure jobs, on decent wages and I had a decent maternity package available, no house bought as ex was army and no real need as we were happy in army quarters as many are, but we had savings and a decent car bought cash, no debts so financially stable.
A variety of health issues including a 2nd mc (1st was at 18 father different), ovarian torsion, endo DX surgery & treatment plus then dh was deployed 3 times in the time we were trying to achieve that.
Other friends/family have variously had pregnancies/babies turn up earlier than planned inc in teens, or fertility issues, mc and stillbirths or other health issues which made getting pregnant a bad idea or difficult...
Some sadly were unable to become parents.
As pp are saying there is no perfect time, certainly not financially, among friends/family again there's been really unexpected redundancies/employers going bust, global financial crises messing folk up, either parent becoming sick/disabled and unable to work, children born or becoming sick/disabled so that at least one parent needs to be a full time carer, parents becoming sick/disabled and needing carers...
You never know what's around the corner, so you plan as best as possible but live based on likely outcomes eg much as on mn there's loads of support for older mums/pregnancies but the reality is that a woman's not only fertility but ability to support a healthy pregnancy declines with age particularly after 35, as do mens but more slowly/less markedly. It may not be a popular view but it's biological fact.
Plus people that haven't been parents/pregnant previously cannot know for certain if they're fertile/able to support a healthy pregnancy until they try to anyway.