What Causes Vaginal Bleeding And Cramps In Lower Abdomen After Alcohol Consumption?

Hi. i have been on noriday pill for a while now . I stopped taking it for about 7 weeks now i had a period last a week wheb i first stopped taking it and then since then nothing. each time i intake alcohol anthing from 2 x 4% cans of beer i have vaginal bleeding red in colour quite heavily i sometimes experience small dark clots and stringy bits. i also experience cramps in my lower abdomen and lower back .