My left boob will get engorge every 4-5 hourly, while my right boob doesn't get engorged even after 6 hours of not expressing. Whenever I express, my right boob always yields lesser than my left. The yield will probably be only half as compared to my left yield. How do I make sure both sides yields the same amount. I didn't have this problem when I just began bf-ing my newborn who is turning 3 months old soon.