What Causes Passing Of White Discharge From Urine After Intercourse?

Hi doctor,I am a male; I have noticed number of times now while urinating, a white substance (very little in quantity) inside my urine especially after intercourse. Again it is a very small amount, and it does not every time come up in the urine, but it is still something inside the urine. My urine is of regular colour as it always is, please I need some feedback, and your advice.Many Thanks.