Ok, You are definately confused about something with the "Sex ed" reference. In my sex Ed Class, they definately stressed that abstinence was the only way to give a 100% guarantee that you would not cause a pregnency or spread any STD's. Abstinence is a form of birth control afterall. Schools can not teach an Abstinence only Sex Ed class - that does not mean they can not teach abstinence in a Sex Ed class.

The "Thoery of Creationism" is a term that doesn't exist, since Creatinism isn't a theory. Creationism (like evolution which it is so often compared to) would be a Concept, that is supported by various Theories (Such as Darwin's theory). The reason Creationism isn't taught, is because there isn't a Theory that supports Creationism. The reason there aren't any Thoeries is that the Hypotheses which would be the foundation of the Theories cannot be repeated or tested, so they can not be a hypothesis and are discarded.