Your supply should adjust accordingly. So if the day feeds are the same or increased, you supply will stay the same or increase, but after a few days you should start to produce less at night so that you don't feel engorged in the morning. But overall you should still have enough milk. It wouldn't hurt to dream feed before you go to bed, but if your baby is still drinking well during the day it shouldn't be necessary. My first DS slept 8 - 12 hours a night from 6 weeks and I had plenty of milk. He was drinking every 1 1/2 hours during the day though.