Plan b

I took a plan the morning after having sex I was on my period when i took the plan b & when I had sex. Ik it’s very unlikely to get pregnant on ur period I just wanted to be extra safe- my period was 6 days it normally 7 days my bleeding became really light after taking the plan b, is that normal ? I took the plan b on day 2 of my period the rest of my period was really light. I’m 5 months pp I’m jw if that’s normal? ( this is my 3rd period since having my son) I never took a plan b before so I’m not 100% sure on what it does to the body tbh