I think i have like a maybe darkish.. Brownish mark on left side of my penis.. I had it for a while. .Not sure how long.. I'm wondering is it good or bad thing..
It's probably just a variation in skin pigmentation.
I wouldn't worry about it, unless it is raised, uneven, or spouting hair, as in a mole growing out of control.
If you like, you can show it to your family doctor at your next regular appointment, but I really wouldn't lose any sleep over it.
There is a topic forum on something similar on this site - oddly under fertility issues header. I have had something similar to this for 25 years, sometimes it improves. It's probably just a skin colour thing. I've been told by Doctors that its a Candida infection but there has never been any improvement using various creams or anti-biotics. I've been tested for STDs several times and always negative.