Could I be pregnant??

hi. i am new here.this is my first time to join a group like this. i am very confused and scared and i have no one to talk to. My last period was may 4. Last may 8, i was with my friends and drinking in their house. she got some friends(guys) whom we dont know. the thing is i went to pee in their comfort room and as i was sitting on the toilet, i suddenly thought what if there's a semen on the toilet seat from the other visitors. I know it's crazy and ignore those thoughts. Then on the last week of May, I got severe back pain. I went to the dr.,it is not UTI.,I became scared and think what if I am pregnant. I was anxious and crying because i dont want to get pregnant. I will lose my job. i bought PT on the first week of June and its negative, but I got some white cervical discharge.,It's my first time to have those discharge and when i looked in the internet that's the first symptom of a early pregnancy. 3rd week of june, y discharge became egg white I was so happy because I know that I am fertile meaning my period is on its way. then my breast hurts and was tender. Unfortunately it's just lasted for 3 days then went back to white sticky sometimes watery white discharge. I tested three times and all negative. I had cramping and whenever I looked it's the white creamy/sometimes sticky discharge. then i got some pregnancy symptoms.,I know it's crazy.,I mean i am not sexually active.but I am afraid that the sperms were on my pantyliner and it went to my vagina 9things like that) i think I will loose my mind. Is it possible for me to get pregnant. If not where is my period. Please help me. Please.Please.