Pain and heaviness of the breasts before periods are natural, just that some women have more than others. Fibrocystic condition of the breast is not a disease, it only means that your breasts are generally a little lumpy. This is natural for many women. It will not effect breast feeding.
A little white discharge from the nipple is also not unnatural and it will not interfere with your pregnancy. But if the discharge is blood stained, then you should see a doctor.