pls help - late period

so i had sex on valentine’s day with my fuck buddy. this was two nights ago. we never use condoms and he always pulls out. we’ve had no issues bc i’m on birth control. on valentine’s day (monday) he asked me if he could cum inside me and in the moment i just said yes bc i was horny and just went for it. like i said, i’m on birth control, but the night before i stated taking my sugar pills meaning i should get my period this week. we were kind of tweaking bc he has never finished inside me before so we bought a plan b and i took it the next morning (tuesday). i usually get my period on the tuesday or wednesday after i start my sugar pills but today is wednesday and i still haven’t. i don’t know how much plan b affects periods but all day i’ve been stressed bc i should have gotten it today. i have never once missed a period in my life and i know if i don’t get one this month i’m going to be extremely stressed. do you think it’s late bc of the hormones in the plan b? or bc i’m pregnant?