Sounds totally normal to me I remember my girls both changed their routines around the 8wk mark also. Perhaps it's a major developmental leap around that stage or like Teni said, a wonder week?
My advice? Just feed bub whenever he wakes and he will fall into a routine soon enough..... there is nothing wrong with your milk supply as long as you feed him on demand, its demand and supply. Your milk is just right for your baby at any one time and your body adjusts to his feeds. Just follow your baby, not the clock - best advice given to me!!!

My little girl is 9mths and wakes different times each night, lately I can't pick it! I think she's teething though so is a bit unsettled lately. I find sometimes she's very predictable with her wake times and other times she's not so predictable. It's all part of the roller coaster parenting ride I think!!

You are doing a wonderful job - good work!!