I went drug free (I had gas for about 15 min dialating from 7cm to 10cm) and it did nothing for the pain just gave me a distraction. The midwives turned it off without telling me just before I started pushing.
I just kept a positive outlook about it. Whatever happens happens but I aimed for a natural, positive labour and delivery. Its a completely natural thing to do and I trusted my body to do it. I was induced at 39+6 due to pre eclampsia and had a 3 hour drug free labour and delivery with no tears, with my first baby!
Good luck!