I recently had unprotected sex with a 22yr old female I was tested for std 3days after with blood and urine tests everything came back negative but now almost 4 weeks later I see a little red mark on my penis head just wondering if it's a coincidence?

Return to doctor. Cloudy urine usually is not abnormal. Urgent urination could indicate infection, but that usually would also cause painful urination, not just urgency. The "red mark" doesn't sound important. This sounds mostly like genitally focused anxiety. But to be certain, return to your doctor for further examination and testing. Good luck!