Painful Red Blister on Shaft of Penis

[seeking_advise]

I recently noticed a small hard white knot under the skin on the shaft of my penis.  It looked as though it would potentially pop with a little "work" so I pressed really hard on it... well no luck.  Instead, the area rushed full of blood underneath the skin, and became very painful.  Well, now it has grown to blister size, and is still a dark red.  The blister is painful, and when I press the blister, it appears to be white underneath.  I tried popping it again (with a sterile needle) but only got oil and some blood.  I have since washed it, and put a band aid on it, but it still hurts...  I want to get tested, but I'm going to wait a week or so and see if it goes away first.

Any ideas?  Would me damaging the skin bring out any dormant herpes or chlamydia?  Is it infected?

I have decided to leave it alone for now, but I want to know if this sounds like any specific STDs...

[seeking_advise]

UPDATE:

Well to my relief, the blister came to a head, and released a massive amount of built up puss (hence the pain).  I've heard herpes don't pop, so it should rule that out.  I have bandaged it up and disinfected well... I'm hopeful that it was just a boil and overstresed skin.  I've had something similar on my face before, and this seems to be following suite.   I will wait until it goes down completely before having sex again (might be painful!).  I had no reason to suddenly have an STD... same girl for 1.5 years now...  Anyone confirm the herpes myth of popping?

[flow1987]

Something like that developing on the shaft of the penis is usually not a good thing. Chlamydia or Gonorrhea does not cause this. Syphilis causes ulcerations, but not usually blisters like the one you describe. This sounds like herpes to me, and you should remain abstinent and be checked by a doctor until he can rule out what it is exactly.