Well!
The first time what was going through my mind was if men did this they would have figured out how to make it less painful a long time ago!
I thought I had a pretty good tolerance to pain because of Kyokushin but it's so different it's not really comparable. There were moments when I felt detached (from the pain) and that may have come from Kyokushin.
One thing I found was my Kyokushin sense of humour and 'desensitivity' did me a disservice. I told the first midwife the baby was coming & she didn't believe me because she'd seen hundreds of births and "I didn't have the right look in my eyes" *panic?*. Between contractions I could still have a laugh. She told me I had at least 12 hours to go & sent me home for the most horrendous 2 hours (because I
thought I had 12 hours of it to go!). Finally decided she was WRONG & rushed to the hospital in the nick of time. Even for your first be confident you will know when it's time & be prepared to communicate that... clearly!
I think it's helpful to try for a sense of calm even if only between contractions & try to enjoy the process & imagine the baby a lot, what it's going through (it's not all about you any more) & how close you are to holding it! And pack food for after!!