Missed period or late?

My period has never been late...It’s been early before (I’m 16, got my period when I was 11). The only sexual act i’ve done recently is a blowjob but nothing close to vag. I had lots of cramping for like a week and now nothing. (I’ve never had cramps before in my life, lucky I know)

My period is four days late...is it just stress or something else?