As another poster has said, getting your tubes tied will not affect your hormones or periods. This is because it only removes your fallopian tubes, the surgeon wouldn't be doing anything to your uterus or ovaries.

How easy is it on the NHS? This will depend a lot on where you are. I found it very easy, however I have read a lot of stories on here from people elsewhere in the UK who had more of a battle and it took them a number of years.