Can your period be 5 days late after taking plan b? i took the pill 4 days after my ovulation day?

Plan B, is emergency contraception you take within 72 hours after unprotected sex. It contains a high level of hormones that blocks ovulation and interferes with the implantation of a fertilized embryo and resets your menstrual cycle. It is not effective if taken 72 hours after you have unprotected sex. Typically the hormones in Plan B cause irregular bleeding, breast tenderness and nausea.