My boyfriend and I have had sex last night, a condom was not used, however, he did "pull out", he also had a firm grip at the base of his penis to prevent any fluids from escaping, he never fully "entered" me and ejaculation did not take place near my vagina. My period is generally irregular, and its only "late" by two days (my last period started on the 1st of December, I have yet to recieve it this month) but I'm very worried. We're both only teenagers and still in high school and neither of us are ready for kids. Last night it was a decision we both immediately regretted and wish we could have taken back but it's too late. I understand stress can affect my periods arrival and I'm trying to not think much on it but how can't I. According to this app, my risk of pregnancy is only at 3% right now. When should I be really concerned about my period? And what are some ways to calm myself so I do not prolong the wait of my period?

I also am showing my usual pms signs : bloating, acne, sore breast, and random waves of sadness. Usually I do not cramp but I had a few stomach pains early this morning.