concerened 😩

so about two weeks ago i took plan b and a week later my period came which was 2 weeks early from the plan b. its been pretty light but today is day 9, ive never had a period this long before mine are normally about 4-5 days and ive never had such awful period symptoms such as a headache for 4 days in a row, sore breasts, cramps etc. but im scared because just when i think its over its not and today is day nine, how long does plan b make your period last? this feels never ending 😭