If your periods are also heavy, I would recommend you try an additional iron pill three times a day for a month. Your periods may be heavy because you are anemic (it's a self-perpetuating thing) or they may be heavy because of hormonal issues (you might want to try birth control pills for a while, they will make your periods lighter). If you have access to a doctor right now, I would ask them to check your anemia.
Have you ever had unusual bleeding in any other situation besides childbirth (like during dental work, or difficulty stopping nosebleeds etc.)? Some people have minor genetic defects in their blood clotting mechanisms, not as serious as hemophilia but enough to cause problems in certain situations - do you know if they ever checked you for those? Has anybody ever mentioned Von Willebrand's disease?
