Thanks everyone for answering me, you've been a great help. The hospital have already agreed to do my tubes. I did however forget to ask them if they clamp or cut - someting for me to remember at my next appointment.
I am going to have it done, i figure while they're in there and its open they may as well - saves me having to go back another time. As for the painful periods - more than a bit scarey (!!) tho it doesnt seem to happen to everyone - and im really hopeing not to me!!!

Thanks again for all your answers!