need answers//thoughts!!!

so my boyfriend and i had sex (protected, but had some malfunctions). i’m not on birth control. i took a take action pill (plan b alternative) the morning after it happened. i did shower and pee afterwards. that was about a week ago. i’m supposed to have my period in 2 days, but i haven’t felt the pre-period symptoms i usually do. is it normal after taking a plan b to have a later period??