where is my period??

okay so sorry if this is like super confusing and stupid but here it is:

at the beginning of october i had a one night stand and we didnt use a condom. he pulled out and then the next day i used plan b and that month my period came a week early than usual. and now for the past month ive been hooking up with a different guy a few times a week but we always use a condom. period is now two weeks late and i just took a pregnancy test just in case and it was negative. i'm relieved i'm not pregnant but where is my period?! this is the most sex i've ever had in my life so could it be my hormones are out of order or something like that? i'm only 20 and i've never skipped a period before besides when i was like 12 when i first got it. any advice is welcome/appreciated 😩