I had my last period on the 20-24 of oct. then i had unprotected sex on nov 1st & then nov7th i began bleeding bright red blood. could i be pregnant?

Too early : Its too early to tell. If you next period is late, you can check a pregnancy test then.

Seems unlikely: Hi. Sex on 1 Nov may have been a good time to get pregnant, but bleeding bright red blood on 7 Nov would definitely argue against successful pregnancy. The only way to really tell would be see if you miss your next expected period then do a pregnancy test.