Help! Period

So I was taking birth control every night for about two packs and then it was making me crazy nauseous so I stopped about 4 days ago. I had my period two weeks ago but I just got it AGAIN last night. what is happening? also is there anyway I can stop it I took a birth control last night in hopes it would stop. it's the last day of school and I'm going to a huge party and really don't wanna be on my period