Why Am I Getting Period Twice In A Month?

hi! i am a girl of 18 years. i am sexually active and everytime i had sex i took either i-pill or unwanted 72 the very next day because everytime i had unprotected sex. since last 2 months i am having my menstrual cycle litle late with less flow but for proper 5 days and within 1 week after the cycle ends i am again having my periods in the same month with less flow but for 5 days. is there anything serious or any chances of getting pregnent?