What to do if I had unwanted sex?

You were actually raped or at least sexually assaulted. Passed out person cannot give permission to have sex, so it was unwanted uncalled for and illegal.

Simply put, you may be expecting a child. By no way is the morning after pill 100 percent accurate. If you haven't begun your period yet, I would take a pregnancy test now and then repeat in a week. Your cycle could have been affected by the morning-after pill. Try not to be concerned; you still have choices, but you shouldn't make any assumptions before the pregnancy is confirmed. 

You report the rape to the police.

You get the morning after pill.

You get tested for std.

Wow, no offense but from the sounds of it you got sexually assaulted! Aka raped! If you want to press charges or tell the police about it you have every right to, just don't shower or change clothes and head to the ER or Police station IMMEDIATELY!! 

As for what to do, you can always purchase an emergency contraceptive pill called Plan B at the pharmacy or they may even give you it at the emergency room or police station. You need to act fast if you don't want to get pregnant by accident. You also need to never speak the to the guy who did that to you again! If possible, file a restraining order on this person. This person does NOT respect you nor respects your personal boundaries and the sooner you realize that, the better you can move forward!

if your holes hurt then YOU HAD SEX.

when you do not want sex your vagina gets tiny tears in it. if you want the sex it does not. get checked for STD's too

check their phones - they probably recorded the whole thing on there

i want to party with you

Time for you to stop drinking.  You did not give your consent for sex so that's considered to be rape.  You need to go to the ER to get tested for STD'S and to make sure you do not get pregnant, have a rape kit done and also to report the creepers who violated you.  Be smart and careful from this point forward and do not hang with people who party like that.

Sounds like someone slipped you some roofies

You should have gone to the police straight after. Failing that you should find out who took you home and report them to the police. They shouldn't be allowed to get away with this or they'll just do it again to someone else.