Hi. I am 17 and just got the birth control shot, i have questions about it but was too nervous to ask the doctor them. I'm hoping someone on here can help, so here it goes... How long until it "kicks in" ? How will this effect / affect my period? (My predicted start day is the 22nd of this month , will that change?) How much weight will I gain? Prom is this weekend will being on depo affect / effect me in anyway?

Please help if you can, it's greatly appreciated.