☼ Don't let some stupid boy tell you that you can't get pregnant the first time, or that if he doesn't ejaculate inside you that he can't get you pregnant. Oh, he can.☼ Don't believe him if he doesn't want to use a condom. He doesn't deserve your sensuality.☼ Drinking anything, smoking anything, or eating anything will not make him sterile, anything short of a vasectomy (the surgical severing/removal the vas deferens). Most, if not any young guys have not thought of such things, nor would they want any sharp objects near their soft parts.☼ Taking "the pill" will not prevent you from getting pregnant. My mom was on the pill and had me and three other kids while "on the pill" it will not sterilize you, it will only make your cycle more regular so that you know when you ARE most fertile and when to abstain from action.
-Your body is still maturing, you might not be having a "regular menstrual cycle" just yet
-Severe stress, -sometimes physical abuse (and the emotional stress resulting from it), also -horomonal imbalances may trigger you to start your menstruation early, then balance out and have none at all.-eating disorders (such as anorexia or bulimia (sp?)) will cause your body to suspend your menstruation cycle.