I went through this when I went back to work after my maternity leaves, too. Like a few of the other moms mentioned, it might be that starting your son on solids may have reduced his need for milk somewhat, and that is normal. Aside from that, if you need to work (and most of us who work, do need to), then don't beat yourself up over this. Stress is an inescapable fact of being a working mom. Just do the best you can, feed him whatever milk you are able to produce, and slowly introduce formula into his diet if you need to. (Maybe it's best to have his daytime caregiver do this, since he KNOWS you can give him the good stuff and will hold out for it! =) You can always abandon pumping, and just breastfeed at night. I did this and it worked well for me. The baby still gets the benefits of breastfeeding and you don't have to go crazy trying to keep up with pumping at work (which is a challenge all in itself!) You're doing a good job, mama, hang in there!!