this is my second month on Loestrin, and the first two to three w...

this is my second month on Loestrin, and the first two to three weeks of taking it everything wa perfect and . then all of the sudden i got my period and i was not suppose to have it not for another week or so i though it was because i started consuming alcohol and maybe it triggered something, i started my new pack today and i still have period..i don't know what is going on so i decided to stop drinking, but i went to a party today and i don;t think i can do it any longer!! any answers?? is it the alcohol??