Google pearly penile papules and see if that fits.
https://en.wikipedia.org/wiki/Hirsuties_coronae_glandis - it's Wiki, but it's got a decent picture (don't open at work or anything).
Probably not as likely, but also google Fordyce spots - https://en.wikipedia.org/wiki/Fordyce_spots (same deal - don't open at work).
They are totally normal, no need for concern. Has your doctor seen them? What did he/she say?
I think you should visit a doctor. This may be a fungal infection as well as some not completely treated STI. Have you been tested for STI only once? If yes, repeat the analysis, better on the day when these spots get bright red.
But before doing this, check what soap/gel you use for intimate hygiene. Such symptoms can be the results of an allergic reaction, even when they are not itchy. Try to use pure, not harsh water for washing your penis, and the simplest soap without flavored additives. My skin on the testicles reddens and flakes because of the soap with flavors.