hi there lee-hozz 57,im guessing that this could be to do with the menopause,im going through the very same thing ...really heavy periods,BIG blood clots and severe back pain,when i asked my doc about this he said "its natures way,of telling you that you are are at the end of your productive life " ! sad really he also said your body "emptying out if that makes sense ...it did to me,just go along to your doctor to be sure ,good luck .x