If i spot after taking plan b is it because its delaying my ovulation?

Plan B: Plan b is used for unprotected sex with contraceptive failure. It works w female hormones. Plan b can prevent ovary from releasing an egg, thickens cervical mucus which makes it harder for the sperm to reach egg & thins the lining of the uterus to prevent implantation. Emergency contraception symptoms can include spotting or bleeding, changes in menstrual flow or your period may be late or early.