my first contractions were just like my tummy had gone rock hard (well, it had!'doh') and that was it, no pain.
then they started to make me hold my breath, and the contraction started making my tummy go hard from the bottom up, like a wave if that makes sense??
and then it went into my back...............
in fact, once it went into my back, I had to get DH to massage me......and told him to do it hard!! the following day, after I had had DD1, I had loads of thumb-print bruises all over my lower back, and DH had very very sore thumbs.
they did get stronger slowly tho, and I do think they had built up over a couple of days as I had felt like I had period pain for the entire easter, and DD1 was born on easter tuesday, my labour starting eastere monday.