Infection would be the condition to rule out. A urinalysis would be a start, but I would also collect samples (either more urine, or a urethral swab) for STDs like gonorrhea and chlamydia.
If the tests for infection remain negative, it may be pre-ejaculate. A prostate evaluate, with a digital rectal exam, should be considered as well. A referral to a urologist can be considered for further evaluation.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b