How many days does Nordette ECP delay the period?

Patient: We had sex july 18 and her ovulation period is on july 17-23,she immediatle drink 4 pills on dosage and 2nd dosage after 12hrs . how many days does the ECP like nordette 21 delay the ovulation period?

Symptoms: Still there is no withdrawal bleeding after the 2nd dosage and its been 12 days. and 4 days from now aug 5 will be her menstrual period.