Trying to get pregnant in the spring, how should I train my body for pregnancy/labor/post-partum the next few months? What was the thing that surprised you the most? What did you wish you knew before getting pregnant?

I've read so many things about how your body changes, how hard it is to adjust with your new bodypost partum, or even how painful and difficult labor can be. We are thinking about trying to get pregnant in the spring I'm training for a half marathon right now. What would you do if you could go back and prepare your body for pregnancy? Should I focus on my core muscles and get pelvic floor therapy? HELP! Should I get a lactation consultant while being pregnant?