HIV is unable to reproduce outside its living host (unlike many bacteria or fungi, which may do so under suitable conditions), except under laboratory conditions; therefore, it does not spread or maintain infectiousness outside its host.
Even if I somehow got blood on my hand after someone had just been in there?
once exposed to air, hiv becomes inactive and UNABLE to infect.
You had no risk. HIV is an extremely weak virus that cannot remain active on environmental surfaces, like toilet seats, faucets, etc. You have nothing to worry about whatsoever.