Will I get pregnant after bleeding from backup pills?

By back up pills I assume you mean plan b. Plan b delayed your ovulation so yes you can get pregnant if you have sex within a certain time frame of taking this pills. So say you take this pills because you had sex and you were supposed to ovulate three days from then. Well that pill is now going to push it back about a week ish meaning you really shouldn’t risk having unprotected sex again for a week or two