Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. You are having frequent urination complain and your prostate examination shows the normal result as well as a normal USG. So prostate problem here seems less likely and you have been prescribed tamsulosin for that so before starting the drug prostate enlargement if present or not should be confirm by transrectal USG examination. Other causes include Diabetes mellitus for that check your blood sugar level. Sometime excessive anxiety also can lead such presentation of frequent urination. If still no cause identified urodynamic study can be done to investigate for overactive bladder. According to course specific management done. Hope I have answered your query. Let me know if I can assist you further.