What Causes Sperm Leakage While Urinating?

Hi this is sameer please help me. Every month once or twiceweek i hav a problem that is whenever i go to pee i see sometimes sperm comning out i dont know what to do plese help me? is this is a major problem or its common.And im married my age is 28 when ever we get sex its discharged in 5 mins or 3 mins.