Beccus, that's really helpful. Thank you.
DS has generally been sleeping through 11 - 7 from 8 or 9 weeks bar about 4 nights. I've usually had a fair idea if he's likely to wake from the amount he's eaten through the day though and its always been on days when he's been down a bit on what I expect. If he has a night feed he tends to have smaller feeds during the following day. So I've been under the general impression he's getting enough. (Again backed up by the fact I can actually measure how much he has been having and its within the upper and lower limits of that calculator).
My problem is this continued pressure that I'm doing it wrong or not feeding him enough, because I'm expressing. The impression I get is its really frowned on, and they don't know what to advise. Its just easy to say "give him more" and to assume I can't possibly be expressing enough and you can't do it exclusively long term.
I wish I could skip the HV, but its not an option for me unfortunately, as they decided we were at risk because of my anxiety. The irony is, its only seeming to fuel it and be what I'm worried about rather than him. I've been told to weigh in at least once a month, as a minimum and I'm worrying about not doing it, especially since this is now the second time they've raised a bit of a concern about his weight.
DS is a happy little chappy who smiles at everyone, is growing (he's very long), has a ridiculously strong grip (and massssiiiiiivvveeee hands) and otherwise seems to be hitting developmental milestones. It just seems to be a battle with the HVs and their charts.
Thinking about it DH said last night he isn't working a week on Tuesday, so it'd probably be a good idea for me to drag him along to the clinic if its still running before the Christmas break. If only for moral support and the potential backup. It'll either be reassuring or he can fight my cause. DS has his vaccinations about 45mins after anyway which is just round the corner.
Nazly, that info from the GP is also useful to know too. I don't want to be in a position where I feel 'forced' into something I'm not comfortable with here.