I have difficult periods, thanks to adenomyosis. Currently alternating between lying on top of the bed with my knees tucked up, with going to sit on the loo every 20 minutes or so to pass reasonably large clots that I assume are causing the weird wave-like cramps that make me want to push 
I have never had a child, so I can't compare it to labour of course, but the rhythmic build to the top of the wave of pain, which then rolls back down for a few seconds before building again, makes me wonder if the muscles involved are kind of doing a diluted version of what happens in early labour.
It's interesting, but I only find it interesting because I've had Feminax and cocodamol to keep the really brutal pain at bay 
So, it doesn't feel like sharp pain now - it's more a desperately bizarre stretching and pulling sensation that makes my head spin and want to sob at times. I know my blood pressure's really low with it too, I'm very light headed, but pleased as I think I won't throw up this month, because I took the meds quick enough.
It got me wondering how other women would describe their own period pain? Does mine sound at all familiar, or is yours completely different?
Pain is so individual and difficult to get across in written or verbal communication, and women's pain is overall treated pretty disgracefully by the medical profession - but thought it's be interesting to see what other women's pain is like.