If i had my period on 30th of sept and it ended the 4th of october and i had sex on the 6st of october what are my chances of conceiving?

Less than 20%: Intercourse 6 days after the start of your period is less likely to result in a pregnancy. Most women ovulate sometime between days 12-16. Your chance of pregnancy is less than 20%. However; timing as a means of contraception is a notoriously imperfect method of contraception. If you don't want to get pregnant, use contraception. If that fails, there is always Plan-B. Best wishes!