you clearly don't understand the issue about the preventative healthcare debate. For starters, not every woman actually uses birth control to just have sex, it can be used for medical reasons like cysts on ovaries or endometriosis, while other women use to control their periods either because of heavy bleeding or severe pain.
Another thing you don't understand, just because the pill form might be available some what more cheaply, doesn't mean it's a viable option for women, there are other options out there that suit a woman's needs. Unfortunately these other viable options are very, very costly, which is why it should be covered by insurance, regardless of where a woman works or goes to school. It should be their choice, not the employers, because they are the ones paying the insurance premiums; either out of pocket or out of their paycheck.
Also, by allowing more women to have access to preventative healthcare, we can reduce the abortions woman are having, did you ever stop to think about that?