I Am 24 Years Old And Last Month My Periods

i am 24 years old and last month my periods was delayed for almost 1 week.I waited for 1 week bt i didnt get periods n i hd to travel so i took primolut N medicine for almost 6 days. n after stopping taking the medicine i got periods after two days on 2nd october n its nt stopping today its almost 13 days. please recommend me how to stop it. which medicine shud i take.