Early period ..I need help pleasee?

Ok so i started this month birth control pills because i had pretty painfull periods and they were not regular. So my doctor gave me cyclessa birth control pills. Today i've got my period before i finish the 1st package. i still have 4 more of the blue pills to finish the package. I am comfused. is this normal?? wasnt I suppouse to get my period when i finish the package. what do i do now, do i still finish the package or do i start a new one. I need help!!! has anyone got this before.??/