My baby is one month old and I am breastfeeding her. Since more or less one week she is crying a lot afer she eats. She is unconfortable just at the end of the feeding and in fact she is not eating so much from each brest. Sometimes she sleeps but awakes quick after sleeping. The doctor told me that maybe I do not have enough milk and that she is still hungry which explains her behaviour and that I would need to give her artifical milk. I woud really like to continue breastfeeding. How do I know if I have enough milk or not?