Talk to Pediatrician on Breastfeeding

How to establish routine of feeding/breastfeeding in twins.how frequent and for how long they should feed. Is every crying a demand for milk?how can I be sure that my breasts are producing milk when the baby is sucking? I delivered twins girls via elwc lscs at 36 weeks(1.9 and 2kg) 10 days ago. They have no routine at all.just after sucking for just 5 min they they sleep and after 10 minutes again they are crying.for that reason I am compelled by family to give them bottle feed sometimes. On the positive side,I have observed their latching has improved over last 10 days.i am also taking adequate milk,water and protein rich diet.