Joint Pain
This was largely (not entirely) my experience too, with my first labour at home. Still waiting to find out about the second! Personally I didn't find the first stage painful at all - uncomfortable, and intense muscular effort like weightlifting (which I used to do), but not painful. But then I was at home, free to move, and very confident. There was nothing sharp about the sensation - contractions sometimes overwhelming, like retching, but I just went with the flow.
What I did experience was excruciating joint pain in second stage, in my pelvis and lower back... my husband said he could see my bones bulging out and this really was pain in the joints; my uterus and cervix were no problem! I think that was probably because my son was 9lb 6oz and very wide (it took a big shove to get his shoulders out too, and then after the shoulders he was still stuck at the tummy!). Probably also connected to my having some spinal deformities in the lower back and pelvis which mean that area is always a little inflamed. Crowning burnt, but I didn't care about that - the `ring of fire' was really no problem, and I wasn't afraid of pushing the baby out.