A paramedic friend told me you should take the gas and air just before each contraction rather than when it actually starts, so counting will help with this too. Definitely helped me as in my first labour I just guzzled it and was totally high on it and useless with it, but with my second (after he'd told me) I was much more in control
The bit where it feels like a Ring of Fire, that means you are very nearly there! After the head comes out it feels easy by comparison.
Upright or all fours is easier but I was gutted that I just couldn't manage to hold myself up.
Definitely keep up and walking as much as you can though.
TENS machine was fab for me. In the late stages it wasn't really killing the pain anymore but
I've also found out shortly before this pregnancy (8 years after my last) that my uterus is back to front? So my cervix is tilted the opposite way or something. I've no idea how that changes the angles of, er, exit though.
I didn't have an epidural in my second birth but only because by the time they got there it was too late - I was gutted when she said sorry there's no time now you're in transition! Nooooo! So I would say ask early rather than waiting. I'd like to think I can go without this time since I have before, but I also don't want to risk waiting too long again if I do need it.
If you poo during labour it's a good thing. You will mostly likely not notice and you will certainly not care :o