Urethral Bleeding:
Blood at the urethral opening can be a sign of urinary tract infection. It can also be a sign of injury to the urethra if associated with an accident, especially when accompanied by a sudden inability to urinate. Blood in the urine and pain when urinating may be present. Swelling of the scrotum or penis is possible.
If you have had an accident, you should see a doctor immediately.
Otherwise, you should consult your doctor for further diagnosis.