Lactation is a natural and fascinating process.
> The breast is not the natural equivalent of a bottle, which empties and refills itself. Milk production is both constant and on demand: constant because lactation never stops, and on demand because it comes when the baby is put to the breast.
> Lactation works under the influence of two hormones discharged by the pituitary gland: prolactin, which causes the production of milk, and oxytocin, which only sets in at the moment of feeding and triggers the let-down (milk ejection) reflex.
> There is therefore always milk available! Even if you have the impression that your breasts are empty, as soon as the baby begins feeding, the lactation process and let-down reflex kick in.
This being the case, there's no need to worry about your ability to breastfeed. The size of your breasts has nothing to do with your ability: big or small, all breasts can feed a baby.