I am really confused. My doctor said that the mini pill does not cause blood clots and that it is the estrogens in regular birth control that do. He says he prescribes them to his patients that can't take estrogens for, one of those reasons being, risk of blood clots. However, I looked all over the internet and other doctors (online) say that it is the progestins that cause the blood clots, heart attacks, and strokes etc. I don't know who to believe. I also know that being pregnant increase your risks and progesterone is the pregnancy hormone. Is my doctor wrong? Do women have higher estrogen levels when they're pregnant?