When the milk comes in

My baby is four days old. From day two I noticed the colostrum was getting whiter and my breasts got a bit "harder"/filled, but they don't hurt. Today was the first day baby boy got the "milk poop" and his weight has gone up. So, I obviously have milk now, but I never felt that "oh wow, now my milk came in". Is it still coming or can it be as undramatic as this? This is my second child and I breastfed my first as well and I remember I was really uncomfortable when the milk came in on day two and it was very obvious when it happened.