I had unprotected sex with my boyfriend on oct 1, 7 days after my period ended. he did ejaculate inside me. how high are my chances of being pregnant?

Any time you engage: In unprotected intercourse you run the risk of pregnancy. Quantifying you 'chances' is meaningless

Low but possible: Hi. Sperm can survive for several days. You hadn't ovulated yet, but if his swimmers are survivors and you ovulated a few days later, well... If your next expected period is late, get tested. But overall your chances are probably low. If it's not the right, might I suggest some form of contraception?! Good luck!