Re: 7 month old... losing milk fast!
As others have said, you're actually pumping a ton! I wouldn't worry about your supply. My 5 month old gets three 4 oz bottles per day at daycare and usually nurses 4 or 5 times when we're together (including 1-2 times overnight). I generally pump 14-16 oz in three pumping sessions per day at work, so I'm blessed to be able to freeze a little extra each week above and beyond the 12 oz that she usually eats at daycare.
I don't mind that she gets me up overnight to nurse. I'm used to it by now, it's nothing like when she was a newborn and I was up feeding her every 2-3 hours, and I think it helps keep my supply strong.
It's very easy for a breastfed baby to be overfed EBM. Just on Monday DD went back to daycare after 2 weeks home with me over the holidays, and they had just warmed her last bottle at 4 PM when DH picked her up. He got her home, fed her the bottle, and I got home 15 minutes later - guess who demanded to nurse, did so, and then immediately spit up a ton of milk? My kid! (I knew it would happen like that but she loves nursing and is used to doing so as soon as she and I are both home.)
I know from talking to my friends who are also nursing working moms that some daycare providers are used to formula fed babies or will immediately give a baby a bottle if they fuss/make noise. We're lucky that our daycare center has had breastfed babies before and understand hunger cues. DD also makes her wishes abundantly clear by trying to latch on to anything and everything.
I'd recommend slowly scaling back how much you send to daycare, educating them on the nutritional needs of breastfed babies as opposed to formula fed babies, and maybe trying a dream feed before you go to bed.
Katie - mom to Lily, 8/5/2010