You got loads of time, Blue. I know a gal just had another baby & she's in her 40s.
But, since you asked, I had my son when I was 29. It was a hectic time with finishing my degree. I didn't want to be too old when he grows up, tho.
Its a balance. IMO, you need to be finished working on you (whatever that means to you) so you can give the most to your child. Because once that happens, its never, ever *just* about you again.
Of course, lots of women do go to school, climb the corporate ladder, etc, while raising kids. But its much, much harder IMO, than establishing yourself first & THEN taking the time for home & family. A truly supportive partner doesn't hurt, either.
Given a choice, I would always want to focus 100% of my energy on a single issue at a time. But that's just me.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh