I truly hope that I don't offend anyone or get any flack for my opinion, but this is something that I do feel strongly about, so I just wanted to throw my 2 cents in.
Before becoming a SAHM at age 28, I spent 5 years as an RN at an Ob/Gyn & fertility clinic - I worked Maternity at a large hospital for 4 years before that (2 years as an aide while in nursing school). Believe me when I say, I have seen everything!
I really believe that this is one of those rare cases when you have to believe the statistics. I have seen WAY more heartache, broken marriages, tears, miscarriages, special needs babies, stillbirths, seizures, and even death in women over 30 who were trying for their FIRST child. I am emphasizing "FIRST" here because it is statistically easier to conceive again and have a healthy pregnancy into your 30s if you've already had a child in your 20s. With that said, I think it is in a woman's best interest, for the sake of her health and that of her child, to have her first baby while still in her 20s.
In my 9 years working with mamas-to-be, I have rarely seen a trouble-free first pregnancy with a 30-something woman - I have never seen a trouble-free first pregnancy with a 40-something mama. I know there are exceptions to the rule, of course, as I'm sure some mamas on here have had awesome pregnancies and healthy first babes well into their 30s or 40s, but I'm just commenting on my experiences.
You have to remember, that this trend of having children later in life is something that women have only been doing for the last 40 years or less - this is not what our bodies are meant to do. We are trying to beat thousands of years of evolution to make life more convenient for us. Your body doesn't know that you need to have a home, car, master's degree, and xxx dollars in the bank before it's ok to get pregnant. Please, this is JMHO - I'm not judging you or your choices. Just remember that all choices have consequences, and if you decide to wait, you might be in for a tougher time than you thought. Then again, only YOU know when you're ready to have a child, and if you feel that you need to wait, then all the best of luck to you when you do decide to go for it