Hi Chris
I have endo too but have had no problems since I had a laparoscopy in Oct 2007 which is good. I had the mirena put in for really heavy periods and these were reduced to almost nothing within 2 months. I really didn't want to get it removed but the migraines were coming every week so I had to do something about it. I would persevere with it and see what happens after a few months, I was lucky in that it worked quickly.
I think if my periods are going to be so heavy again then having a hysterectomy could be an option as I'm 48 and not going to be wanting more children!!
Hope things work out for you x