plan b symptom?

Hello! Had unprotected at midnight Sunday night right when it turned Valentine’s Day. He didn’t finish and wasn’t even close.

Valentine’s Day at night, I took a plan B.

Now today, Feb 22 I am experiencing some light pink spotting.

I know that is a side effect of Plan B and Plan B affects everyone differently , but this bleeding wouldn’t be implantation probably, correct?

I had sex 10 days ago, but it was only 1 day after my period, so I don’t think it could be implantation bleeding?

I will take a test if I get super stressed, I’m just looking for some insight as I’ve never taken Plan B before (I did read label, it’s just these timelines are weird)