H.1.
You're not the only one to worry this much in pregnancy, trust me :)
I worried all the time as well, but my mom was always telling me "well WE never did that/worried about that/stopped this" etc etc etc. And this helped me, because it's true for most things I was worrying myself over. Our parents didn't stop drinking caffeine (mom thought I was nuts) and I doubt they knew not to lie on their backs, etc. My advice - do the obvious safe things (no drinking, smoking, etc.) but all the extra do's and don'ts you should try but don't drive yourself nuts over it. The stress from worrying is probably worse for you and the baby. Your baby is super protected in there :) Also, you will have plenty to worry about soon enough! Any specific worries, ask your doc