Best time to start having children, while minimizing career derailment?

I didnt read all your question too long, but from your title i can tell you life is short & you are not the 1st to live its all been done & we are still alive, do what you want when you want it nobody can tell you how to live if you want a kid have a kid & deal w/ your life career the rest of the world does dont make your life complicated or it will pass you by W/OUT A CARE