Is it possible to be pregnant ?

So none of this seems possible since i last had sex last month on the 15th same night i took a plan B and i bled for two days after that and started ovulating after i took the plan B so it should’ve worked right ? And then i had what i thought was my period for 4 days from 19-22 but now my period is 6 days nearly 7 days late and I’ve been cramping like my period is on its way and peeing a lot but nothing yet and i haven’t had sex since the plan b