Once my penis once while wave jumping. It took a few days to heal. I don't know how long it took to heal. But would not worry about it unless it does not heal with in a week or two.

Could be it b a birthmark?

I noticed it about 4 months ago, so i would have expected it to heal by now. It maybe a birthmark as it's not causing any problem to my knowledge, however, wouldn't i have noticed it earlier..?

A birthmark would be noticable since birth...not 4 months ago.

I'd still have it checked out...

Totally agree with the Zig. Get this checked out, better to be safe than sorry!

Thank you to everyone that posted a reply. I took your advice and went to see my Doctor but the most annoying thing is that it was hardly visible. So i explained to her that its noticeable after i do sports or anything that causes alot of moment and she said its nothing serious as it only occurs when blood is in the penis or your sweating. She said its nothing to worry about it may go away or stay there but already i have noted that its not that visible, may be where a collection of viens come together or a burst capillary which heals and dissappears over time. Once again thank you.