Took plan b a week before period

The start date of my last period was jan.24th, my expected period according to the 28 day cycle would be today feb.21st. My cycle tends to switch up from time to time. In january my period came a day early than expected. In december, my cycle completely changed from the beginning of the month to the end.
I took Afternath (Generic version of Plab B) on feb.13th a week before my expected period. 
My period didn't arrive today as expected. 
Since I took Plan B a week before my expected period, could that make my period late? 
The waiting process sucks. Trying not to stress for fear it'll delay my period more. PLEASE, if anyone has experienced anything similar to this, or can give me feedback please comment😫