I Had Just Gone To Collage And Went Wild With

I had just gone to collage and went wild with drinking and smoking. I had unprotected sex with my boyfriend regularly all of June and July, during the month of July i remember telling my boyfriend i was ovulating and he came in me. I missed my period August and i noticed spotting on the 9Th of august and had an expected period on the 12th which i didn't see. i then had unprotected sex with another guy on the 8th of September and he ejaculated in me. I'm scared to go to the hospital. How far along could i be? Who is the father?