Once you notice that your baby has stopped swallowing milk and is now just comfort sucking and falling asleep it means that they are no longer getting a good mouthful of milk. (breastfeeding-babies.com)
Our boobs leak, our baby drools a mouthful of milk all over us, our nipples are sore. (mommasociety.com)
This pause that is visible at the baby's chin represents a mouthful of milk when the baby does it at the breast. (breastfeedingmums.com)