It just looks like a blocked pore to me. I bet it's gone by now, if you've left it alone. If it persists and you're still worried, show it to a doctor, but it does not look like an STD.
Take care.
Dr. Rockoff
Chancroid is very rare and looks nothing like your picture. No more research, please--just get yourself examined.
Dr. Rockoff
I forgot to mention that I am afraid it might be Chancroid, since after research I found out that is it usual in latin america
by the looks of it, do you think it is possible? what should I do? I had never consulted a doctor for a similar matter before and I am a little embarrased to do so, is it smart to wait some more days?
It is unlikely you got chancroid from the incident you describe. It could be random trauma. Chancroid is treatable with antibiotics and is not that serious if you get it treated. Go to an STD clinic and get it looked at. The people at STD clinics are excellent in my experience. Just go and get it checked out, you will be fine (better than freaking out - do something constructive). Bets of luck.