why she is not getting pregnant.

Patient: My wife got period everymonth on due date normally. I got married in feb 2013. From last three month we are trying . During my sex i release thick sperm in my Wife’ s vagina, after that the thick sperm return from vagina slowly. is it reason for negativity of my wife. The size of my penise is 4 -5 inches..I don’t know , why she is not getting pregnant. Please give the direction

Doctor: