Hello and thanks for your query. I shall make an effort to provide you with good professional recommendations specific to your questions. Based on the information it is most likely to be due to some inflammation either in seminal vesicles or prostate or urinary tract infection. It can be easily diagnosed i would first asked for urine analysis, and based on that i would have given a course of antibiotic. Even after that if it persists, then a semen analysis can be considered. Presently i would suggest you to drink lot of water and cranberry juice which is helpful in UTI and to see doctor for examination as it is difficult to diagnose here without examination and investigation. I do hope that have found something useful to help you and I shall be glad to answer any further apprehensions. Take care.