What Causes Delay In Periods?

Hi doctor ,i have irregular periods.since 3 months i don't get period.for that reason my doctor gave me lupride injection everyday 1ml for 5 days.doctor said that u will get period before 1 week after completing dose.this is 11 th day but i don't get period.doctor also said to me in my cervix i have cysts.before this injection doctor gave 10 tablets for getting period,but i don't get period.pls give me reply what i will take next step.