Hi! My Period Is Usually Late And Very Painful. Sometimes

Hi! My period is usually late and very painful. Sometimes it's longer, and sometime shorter. I wanted to regulate my period and I'm interested in going on birth control. My period is due any day now but I haven't got it yet and j was wondering if I am prescribed birth control within the next two days, will I skip this months period? ( providing that I don't get it within the next two days)