Period began 8 days ago, not on bc & i had unprotected sex while still on my period (day 4/5), bright red bleeding 8 days after period, am i pregnant?

Be safe; check: You are not likely to get pregnant from one episode of "unprotected sex while still on your period (day4/5)"; but if you have been having genito-sexual relations without any form of protection against pregnancy and against sexually transmissible infections, do seek a gynecological evaluation, a blood pregnancy test (beta HCG) and screening tests for STI. Be safe. Check; if neg. ask for a LARC.