Did you know that breastmilk is built up by supply and demand? If you are nursing exclusively it is very very slim chances of your milk 'running out'. Some people have medical problems that cause their milk to dry up but otherwise having no milk is not the cause of your breastfeeding problems. This is the #1 complaint that i heard from my DH's family that had tried to breastfeed-"oh, i just didn't have enough milk so i couldn't breastfeed" Most likely that is not what happened and people just start worrying too much about how much intake their child is receiving. By watching the amount of wet diapers your baby is having you can make sure that your child is receiving enough breastmilk. If they are having at least 7 wet diapers a day then they are doing great! 
