Have Not Had My Period Since March An Having A

Have not had my period since march an having a right breast discharge I complained to my gp and he gave me progesterone injection and my period came after 5days so I could run a prolactin and progesterone test and the results seems fine. He as asked me to take primolut n twice daily for five days, I want to know if it woul come normally after taking this grugs or I would have to continue using it anytime I want my period.