Question just about birth control pill, to stop term?

I'm 12 and I've had my term for about 7 months, and I own a couple of questions roughly speaking the birth control pills
what exactly do they do and can they really not only regulate but entierly stop your extent??(I wouldn't use them now, but for when I'm contained by college or sumthing)
I also read online that there can be profoundly of side affects to them. I guess I want toknow if they're safe, and what I would involve to know if I wanted to use one. Becuz my term is really annoying and I don't like using tampons uet and stuff.
Another fast question, whenever Iuse a tampon for sumthing similar to school or a physical diversion (i haven't swam with one on the other hand tho) it always ends up leak! am i putting it in wrong? or do i purely need a super??
(and yes this isn't my acount, I know it say I'm a boy) The pill is safe and it will regulate your period but if you want your periods to stop after there's the injection that you have to own once every 3 months
sometimes tampons do stop your period approaching birth control