I had a drug free birth this time, partly due to a quick labour (3 hours) can't tell you I would've stayed drug free if it was longer though. But I did use a TENS machine. It's totally drug free and non invasive, you stick it on your back and it send electronic messages to brain which distracts you from labour pains. Im not sure how much it helped but it certainly distracted me (particularly the three times I turned it right up instead of off... OW)!!! anyway, it was $10 a week to hire from a physio. Youcan call your physio and they'll give you a go. really worth trying. I had mine on up until about 10 minutes before bub arrived.
Good luck oxox