Birth control works by making a woman's body respond to stimuli, in multiple forms, to act as though it is pregnant. While this would seem like a good thing, the side effects that accompany being pregnant, also accompany the use of birth control. Additionally, birth control is often marked as a good measure to prevent unwanted pregnancy, which can lead to complacency, and disregard for signs of ovulation, which could on its own lead to an unwanted pregnancy when birth control is missed or fails. We ignore the side effects for the sense of control it provides, we conveniently ignore the side effects of birth control.
I no uncertain terms, in my experience on birth control, it is a fairly unsafe drug that can cause far more harm, then falling pregnant. I believe these problems are overlooked by the public and health professionals because we as a society feel we have been saved by birth control. In truth, we have prevented many pregnancies, but there are many women who have experienced the bad side of birth control as well.