My ovulation cycle

Right I get confused by this do you have sex all the way through your ovulation window or have sex leave it for three days then go again as im getting told alsorts and don't know what to believe I know people aren't doctors or health professionals but I need some sort of advice please thank you and for a man that has low sperm count does it really work dipping balls in cold water before having sex as my partners doctor told him that but just wondering if it's actually true thanks for reading