Help…

So on December 24th my boyfriend came inside me the very next morning I took plan b. I know plan b can possibly delay my period by a week or so. But now it’s January 1st and my period is 4 days late. Should I be worried about my period not coming at all and possibly being pregnant or am I overthinking/ stressing and my period is just delayed cause of the plan b…..

Need advice from ladies that possibly experience the same thing after taking plan b