With in the past 2 monthes, after what I thought could have been a UTI, but later it went away. During ejaculation occasionally small (end of a pin) sized yellow "stones" appear. These cause a sudden startle but not to much pain, but definately discomfort. After researching what I could they appear very similiar to cystine kidney stones, but as far as I know do not show up in urine. No other testicular pain, discharge, or discomfort is present. What could this be?