My 13 wk old is a good feeder has both boobs at each feed - goes 2.5/4hours between feeds at day and sleeps for 6 hours staight at night before going back to normal daytime pattern. Over the last few nights I just can't seem to satisfy him (he had a growth spurt last week). He is now 17.5lbs. After 1 hour of feeding and pulling/dropping both breast my husband who is very supportive of BF said it was unfair to not give him a bottle of formula as he was obviously still hungery. Tonight I gave in and he downed 8oz before stopping. I feel this could be the beginning of the end - I've tired expressing but only got 1/2oz, so very little milk. I think I'm going to start mixed feeding - any suggestions on how best to do this? I have two other young children (2&5) and see this as the best solution.