Emergency contraceptive- could I be pregnant?

I had a one night stand a week ago. And it was on the last day of my period. I took an emergency contraceptive the next morning, (a week ago). Now i’m bleeding again, exactly a week later. Google has made me go crazy, could I be pregnant. I read something about an “implantation bleed”.

Ps. He pulled out every time. But I know that doesn’t work as effectively.

I’m also off all my birth control because it messes with my system way too much.