Just thought I would toss my $.05 $0.25 (it got long) in here. DH and I were not emotionally ready until well into our 30's. Tried, got pregnant, miscarried - the early miscarriage rate is more like 1/3, so not unexpected. When that happened it was amazing how many women I knew told me they had also had a miscarriage and not to be thrown off by it. Anyway, a few months later we started trying again - DD was born just after my 39th birthday. No problems, but I did notice that women who give birth at a younger age did seem to recover faster. However, women of my mother's and grandmother's generations had babies well into their 40's, they just were not first babies. Plus I had friends who were the youngest in their families by at least 10 years - oops babies, they were called then - the start of menopause gave people a false sense of security ;-)
A few biological thoughts - women can have babies with chromosomal abnormalities at any age, your eggs have been sitting there almost ready to go since before you were born. Yes the odds go up with age, but they are never zero. The time to think about what you would do if there were chromosomal abnormalities is before you get pregnant, not while the doctor is asking you if you want an amniocentesis. In my province, at my age, they assumed I would want to know, but would not have done the amnio if I had said that I would never abort, no matter what the genetic situation. And there are abnormalities a lot nastier than Down's. The other biological issue is your SO, men also have reproductive issues, and genetic reproductive issues, as they age. So you would both need a through physical to see if there are issues. I have known couples who were infertile in their late 20's, so again you don't have to be in your 30's to have problems.
So the take-away message here is to figure out what is right for you and your SO. Not that that is easy, so good luck.