sudas: If you're concerned that this relates to fertility, you could try holding off ejaculating for a week, to see if it changes. If no change, try staying out of the hot tub for a week. If no change, then maybe try boxers for a week. Remember the scientific method is to separate variables.
When the microscope was invented, one of the first things observed was semen. I'm not sure what the magnification is needed to see the sperm. Just don't use the one in biology class for your home project. :D