Bleeding after plan b

So I got off my period a week ago and had unprotected sex. Usually we pull out but this position made it hard to do so and he didn’t pull out fast enough. I took a plan b that night. Now a week later I am having some bleeding. I can’t tell how heavy it is yet but it’s more than spotting. Should I be concerned? Online says bleeding should happen within 2-3 days of taking it if it occurs. I just wanna make sure this isn’t implantation bleeding. I understand I am an adult and have my own risks with unprotected sex. I am coming for opinions on the bleeding not my sex life thank you.