Everytime I pump out the amount of milk is 40ml but when u I breast feed then pump the amount decrease to 20ml. Does it mean after breastfeed for 30mins, LO only drink 20ml??
It's not accurate, if you want to accurately measure how much baby drinks you can buy a baby weighing scale and compare his before/after weight. Or go to lactation consultant, they can help you measure! They can help with your supply concern as well.