one red bump on same spot on the shaft of the penis

About 8 or 9  times in the last 5 years or so, I have gotten a red bump on the exact same spot on my penis. Most of the time it has happened right after i shaved my penis, but a couple of times it has happened when i have just trimmed my penis hair and once it just happened without shaving. I have never popped it and it itches and hurts to touch for the first few days because it swells up, then it goes away on its own. The full duration from the start of it until it goes away is about 2 weeks. There is always only one red bump and no more and it is always in the exact same spot on the left shaft of my penis about halfway down. What could it be ? worried ?  

[daisy315]

To err on the side of caution you should have a Herpes test done since it is something that keeps re-appearing,until you get a test done i would treat this as suspiciously similar to Herpes I'm afraid. But do please remember we are not Doctors on this Forum and even if we were we couldn't diagnose whether or not someone definately has Herpes we can only advise on what we think the symptoms may indicate in our opinion,that does not mean we are always correct.

Daisy