I try to do both as 1 breast doesn't seem to fill him. I let him stay on the 1st one until he pulls off which is normally 30-40 mins then the other side for another 10- 15 mins. I just caved and gave him some formula, he's now happily sat and not screaming. I know dh would secretly prefer me to go on formula o he could help. I think expressing will just take as long as feeding. This morning I fed just of one breat at 5am and the other one at 8am, and then expressed from both at 9am. I got 1oz between the two. Surely at 5 weeks I should be getting a lot more than this?