I am heading back to work next Monday and I am worried about pumping and making sure I have enough for Sean. How do I know how much to leave the babysitter? I have milk frozen in 2oz and 3oz baggies. I have 10 baggies right now and will get more when I am back to work and pumping 3xs a day at work. I have no idea how much Sean eats, how do I know? He will be 6wks old. Any tips for me while heading back to work?