You know what you cant prepare for it 100% ...
I would suggest you stop worrying about it and enjoy the pregnancy right this minute or else you will go mad with worry lol
I have had two baby's and the two were totally different but vaginal births.... first one i had epi and vaccuum (long long labour) and second one i had one shot of peth and sucked on the gas (4 hr labour)
I honestlt would suggest to you to have a open mind about how your baby comes into the world ok ...... yes you can try a drug free labour/birth or if it gets too much you can ask for some pain relieve...... we live in a time that drugs are there to be used in childbirth if you want to use them.
Enjoy that growing bub and have an open mind