How do i know whatit is?

So i have a bump forming on my lip line. I just noticed it this morning/afternoon, To me it feels like it’s a pimple forming but my friend said it could be a cold sore.

It hurts like a stubborn pimple about to happen…

I was wondering how do you know if you’re getting a cold sore? Is it the same stages as a pimple?

I haven’t seen my bf since last month and we haven’t kissed or had sex since early February… if it was a cold sore wouldn’t it have shown up by now?

Should i be concerned?

You can’t see it but I’m trying to point to it and it right next to my finger below the lip line