Yesterday i fainted while in the shower, i am fairly healthy as far as i know? i am on bc pills and all i had to eat beforehand was toast and tea? why?

Who knows?: Spontaneous loss of consciousness in a teenager needs to be reported to their legal guardian, and the patient needs to be evaluated by a medical doctor, period.

Fainting: Fainting is benign on most occasions and is caused by sudden drop in blood pressure and short lived poor brain perfusion. Since it happened in the shower, it may have been that excessive heat caused peripheral vascular dilating with brain blood flow compromise. If you have only a small meal, chances are your sugar level was low to allow that to happen. If it's a single episode, i'd not worry much.