S.
Kristin,
I hate to say it, but if you have any sort of possible blood clotting disorder, any estrogen based hormone birth control is out of the question. You could possibly try the mirena IUD, it contains progesterone only. I used it and had it removed due to complications, but I know many women who have used it with great success. And it thins the lining of the uterus, so that may help with the endo.
Natural family planning is always an option!