Breastfeeding mamas!!

So my LO Is now 3mo old and she is starting to sleep longer hours at night (4-5hour stretches) while I love the amount of rest i am getting, and happy about my supply of milk, sometimes I wake up with my boobs engorged and lumpy hard all over, and painful - im worried about the possibility of Mastitis... I pump but I am not sure if Im signaling my body to make even more milk.. Anyone experiencing this? Do u just deal with it and hopeing your supply will adjust or do u pump away?  At what point could mastitis be mistaken for engorgement (or could it!?). Thanks in advance!