If you have delayed taking the pills by 4 days, then before the pill takes its effect. It is important that for at least 2 weeks you follow an additional contraception method in form of barrier contraception in case you are sexually active to prevent any chances of pregnancy in these 2 weeks during the cycle.
I hope I have answered your query in detail,
wishing you good health,
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.