If I were you then I wouldn't bother with the pumping - DS is about 4 weeks younger than Isla - he also sleeps through (so similar in that respect - also in the trying to latch on through clothes if he gets anywhere near my top half :-)) if I try to express of an evening I get nothing at all - so as am sure you already know what you get from the pump is no indication of what you have and if it were me the seeing nothing would have more of a detrimental psychological effect on me than any benefit that the stimulation from the pump might give. Unless you find pumping relaxing I would dig into a tub of ice-cream or whatever else it is that helps you chill out instead.