The morning after pill is a high dose of progestogen (a synthetic hormone which replicates progesterone which is produced by your ovaries). The sooner you take it the more effective it is. It usually delays or prevents ovulation, although it may prevent implantation by altering the lining of the womb.
I'm not sure where you are but here (england) the type usually used is a singular pill. I can't tell you how to obtain it anywhere other than here but if you are in england then go to your local famiyl planning clinic or your doctor (you can buy it over the counter if you're 16 ). You must take it within 72hours of sex.
You may feel sick afterwards but if you vomit within three hours then you'll have to take another as it wont work (although most women aren't actually sick). You may also have a bit of spotting between taking it and your period and your next period may be delayed slightly.

If you are planning on having sex regularly then you need to think about contraception and should speak to a professional about it. Also, at your age (or any age for that matter) make sure you're engaging in sexual behaviour for the right reasons and not because you're being pressured or feel as though you "have to"

she is 13 here and 12 in the pregnancy q&a board..Haha people kill me man!!

Lol why do people post different stories on the same forum! Its so dumb

I hate when people do that too. . .It's so freakin annoying!

Whether she is 12 or 13, i'm gobsmacked that she is having sex so young!! :shock:

Just a troll,ignore her. . .

If you're in england you get it from the pharmacy. Sometimes they ask/make? You fill out a form before they sell you it.