After a very slow start, I'm finally managing to exclusively breastfeed my 4 week old son. He wouldn't latch on until he was about a week old, and I had to use a pump to bring my milk in. Up until this past week, he's been fed on a combination of formula and breastmilk, and has gained weight well. However, this past week (since he's been feeding off just me) he's gained hardly any weight at all. What has confused me most, is that up until recently, I could easily tell when my breasts were full as they became quite firm, and softened as he fed. However, now, they barely seem to 'firm up' at all, and don't really feel any different after a feed than before one. He doesn't pull off me in frustration, but will often only feed for 10 mins or so, and I can't work out whether this is simply because he's not hungry, has wind or has run out of milk. I usually squeeze my breast when he's done and can usually still produce milk. I guess what's really bothered me is that this morning I had to go to hospital and left DS with my mum who ended up giving him a forumla feed as I wasn't back in time to feed him - and he guzzled loads - about 150 mls. When I got home, I pumped and could only produce about 80 mls from both breasts - and quite often when he feeds from me he'll only feed off one. I don't really know what to do. Any advice?