Re: sperm in urine?
You say you are not sexually active, but you do masturbate and have ejaculations, right?
It is possible you have retrograde ejaculation, which is a condition where the valve that supposed to close off the urethra leading to the bladder doesn't close right. The result is that some or all of the semen that normally comes out of the penis backflows into the bladder. It will stay there until you urinate, usually causing cloudy urine. Sometimes the valve can close the wrong way differently, causing a bit of urine to mix in with the semen being ejaculated. This is usually seen as larger than normal amounts of watery semen.
When you say a few drops of sperm, is it white like regular ejaculate? Or is it clear and sticky?