Question about milk coming in

acmayn01

This is a really dumb question because it seems like it'll be obvious, but will I know that my milk is about to come in? It's been almost exactly 5 days since I gave birth (c-section really early Tuesday morning) and I've been BFing since recovery. LO is having a good amount of wet diapers and was having tons of poos but in the last day that has slowed down. We do have to use a nipple shield because of nipple/latch issues.

My breasts have felt heavier since Thursday but it's not obvious to me that my milk is about to be in. Any suggestions? Will it become very apparent? I'm expecting engorgement, etc but not exactly sure.