A little red dot is very unlikely to be an STI, but if you are concerned, you need to go get it checked by a doctor. No one online can tell you what it is.
It might be an irritated hair follicle or just an irritated spot, or clogged oil gland, but only a doctor can tell you for sure.
You should know that STDCheck's 10 panel test doesn't include tests for mycoplasma, and there are no tests for HPV for men. There is no such thing as a "full panel" to mean that you are fully STD free.
Also, I've had genital herpes for 20+ years. I'm a professional woman in an managerial role. I have an advanced degree. I can count the number of partners I've had in the last 20 years on one hand with fingers left over. There was a time in my life when I was "promiscuous" - I didn't get herpes then. I didn't get herpes until I was in a long term, monogamous relationship.
"Classy" is a matter of opinion, of course. I don't particularly care about that and make no judgements, but how you dress, how you act, where you work, etc., is not an indicator of STI status. Anyone and everyone can have an STI.
I disclose my status to all my partners, but my sexual health is MY responsibility. I do not rely on my partners to be honest with me. Your sexual health is YOUR responsibility, and your fear of STIs is on you to bring that up with your partners.
You are a fully grown man. You know enough about STDCheck, so I assume you know about condoms.
If you ask someone about STIs and they don't disclose, that's one thing. If you just assume, that's something else.
Yes, I'm being hard on you. Preventing STIs and STI stigma is on all of us.