I dont consider myself to have very good pain threshold, but I managed from begining to end (over 30 hrs) without anything till the very end (peth), and in hindsight I could and should have done without it.
Go in to labour with the expectation that you probably can do it without drugs, but knowing that they will be available should you find it too much. You can put this in your birth plan and do a bit of research first to see which drugs you would prefere over others. And have support people with you who can encourage you and believe in you.