<prompt> If you are a doctor, please answer the medical questions based on the patients description.After oral sex I noticed a small black mark on the head of my penis which I presumed to be a blood clot. I have had it for the last two days or so and it is still apparent after this. How long should it take for it to disappear? and should I see a doctor if it persists? Also could I take the matter into my own hands by popping the clot with a sterilised pin or would that be unadvised? Any advice would be appreciated.  <response>: Degree understand your concerns went through your details. Please do not do any sort of interference without a doctor advise. The black spot could be anything from a simple mole to a blood clot. Blood clot takes around 15 days to 30 days to disappear. If it is herpes like blisters or any other infections you need the advice of a dermatologist. To be on the safest side, please consult a dermatologist. Take care. If you still need my assistance in this regard, please use this link. Please remember to describe the whole problem with full detail. Hope this answers your query. Available for further clarifications. Good luck. 