Why there is no sperm coming from penis?

several factors could affect sperm production including:

# age- some people are late bloomers, old people stop producing sperm

# temperature- very cold or hot temperatures kill sperm # pressure- tight undies kill sperm # diseases- cancer, and other genital diseases at your age, you shouldn't worry about your sperm, unless your trying to repopulate your neighborhood, or you probably have mistaken sperm from semen. anyway, you should go seek someone who specializes in this kind of matter....