He should be better then the pump. It could be though that either he is having a growth spurt OR it is that he isn't attaching well enough to effectively drain the breast.
I also have been suffering with blocked ducts (probably is mastitis but im just pumping feeding handexpressing as much as I can to get it out) & while Rohan is feeding well etc. I think he is attaching poorly tot he effected side. So I really have to pay attention on that side when I get him on.