I've always had very strong period cramps on day 1, before having kids they were "roll around on the floor crying in agony begging the universe for relief" cramps, but after giving birth they calmed down enough to just be called strong cramps. During labour, I contract fast and hard, it feels soooo physicially productive, 2 of my labours were a few hours ( first and third baby, 10 hours and 6 ish) and one was well....I'm not sure...time between waking up and baby literally shooting out was about an hour, maybe an hour and a half- I think the majority of the cervix dilating contractions must have occurred while I slept. It was pretty funny yelling "Catch!" at a midwife while hanging on to a chest high bed!
Pregnant with my 4th, and perhaps a little too confident about labour, I hope I get lucky again!
So for me, strong period cramps and strong contractions are a thing. Minimal pain relief with the first 2, none with the third (hated pethidine, and gas and air made me feel drunk- not a fun feeling for me while trying to focus on labour lol).
I must add, with my first, I went in as soon as my waters broke, which was right when labour began, and they looked, saw I was 2 cm dilated, and asked if I wanted to go home. I said nope! Drank some raspberry leaf tea and about 3 hours later was up to 8 cm- the hard part was letting myself push when the time came, because I was scared of the unknown, that kinda dragged things out a bit and they almost had to "get the doctor in" which I knew meant possible episiotomy, which scared the heck out of me so suddenly the unknown sensation of crowning was a lot less scary and he was out in the following push! The crowning bit just stung in the end, nothing too scary. Fear of the unknown is a bugger!