Yes I think they do feel different for everyone. I find it hard to describe mine, it was sort of pain in all of lower bump, like the worst period pain ever, plus lower back pain. I also lost more plug with each contraction. I reckon this could be it for you!
I had contractions in my back too, it was because my baby was back to back. If you are having "pains" regularly then i'd think they are contractions. Mine did get progressively worse as labour got established, I would call your assessment unit for advice, but it sounds like things are getting going!
When I had my dd all my contractions were in my back after being induced four times in a row. All I remember is feeling like my back was breaking in half every three mins or so then ended up with an EMCS.
This time round I have realised I don't really know what to expect if I go into spontaneous labour. I know what BH feels like and sort of assumed it would be like that.
I am 40 + 4 and keep getting this really sharp intense pain that takes my breath away deep in cervix area. It feels like twisting/stretching and it does have a peak and then goes away again. It lasts for approx 30-40 secs and is happening every eight mins or so. It went on for hours the other night and I called labour ward who told me to stay at home. They went away. Since then I have had three bloody shows. Now the pain has started again. Every eight mins.
I have a nagging back ache constantly and sometimes during the pain my back hurts a bit but no 'tightenings'. It's all really localized. Baby is OP apparently.