I finished my period on monday last week and had the morning after pill tuesday now i have started another period on sunday? is that normal?

Maybe not, but...: Taking a morning-after pill (such as Plan B) can alter the timing of the current menstrual cycle and the upcoming cycle. Menstrual bleeding or spotting should be back to normal, after 3-5 weeks or so. One should check a urine pregnancy 3 weeks after taking the emergency contraception pill, to make sure there is no pregnancy. Home urine pregnancy tests are very accurate, and sold everywhere.