Is Birth Control Recommended In Case Of Heavy Period?

yes Ive recently started taking birth control since last Saturday and the reason i started taking it was that my periods were very heavy and were not normal so my doctor recommended the pill. i took the pill the day when i started my period which was last Saturday and its been nine days and I'm still on my period. why am i still on my period? the longest Ive lasted is up to 5-6 days is there something wrong with my body?