<s>[INST] HiFor the last two days I felt a little pain while urinating. Today when I had sex the sperm was brownish colour and watery. It had never happened to me before.I'm a healthy 24year old male, dont moke and go to a gym 3-4 times a week.Should I be worried that I got an STD? I havent slept with another woman (other than my girlfriend) for almost 2 years. She had STD check up about 5 months ago and it was clear. [/INST] HelloThanks for query .Pain while urinating with brown colored semen is suggestive of infection of prostate (Prostatitis).Consult qualified Urologist for clinical and digital rectal examination and get following basic tests done to confirm the diagnosis.1) Urine routine and culture. 2) Ultrasound scanning of abdomen and pelvis3) Semen Examination and Semen culture ,In the mean while start taking antibiotic like Doxicycline twice daily and later on switch on to appropriate antibiotic as per culture report .Please note that Prostatitis takes long time to get cured hence you will need to take antibiotics for 4-6 weeks .Dr.Patil. </s>