Pregnant or not

Okay so i had sex with my bf on sep 8 and we had unprotected sex, but he didnt come in me. When he pulled out there was some milky white discharge on his d*ck and I got scared. Then the next day I was spotting and it started to get more and more heavier when the days past and it disappeared. Plus lately like 2 days ago my nipples have been feeling sore. I’m worried that I’m pregnant but the thing is he didn’t come in me? So I’m wondering why was I bleeding the next day after sex?