Thanks Raven,

I've noticed the racing heart too when i get the tightenings and if I'm being particularly active,(and after orgasms). Good to know that they are prob BH, but then what is the Period like cramping i sometimes get?
Sounds exactly like them...especially after orgasms! Very hard to get out of bed and grab your knickers when your uterus is like a bullet after an orgasm..or is that just me

I sometimes get a period ache with them as well especially if I'm lying on my left, and it starts to ache down one leg like toothache too. I think different positions might make a little bit of difference when one strikes