Neurotic mother alert. 4 month old weight gain

[Penguina]

Am bfing ds exclusively. He is 4 months. I have weighed him every week as I have an aquascale bath and am a bit obsessed with measuring as I have a disabled daughter who was tiny for such a long time. He had been gaining really well (born 7lb 3oz, 25th centile and now 17lb something between 75th and 90th) but this last week he hasn't gained at all and has perhaps even lost. I didn't weigh him at the same time this week but am really paranoid now?! He used to feed at least every hour if not more but is going 2hrs sometimes now.
I have also lost half a stone in a month, could this be why? He seems to be getting enough milk as he pukes it everywhere and I can feel him swallowing

Do I just need a slap round the chops and to be told to stop weighing him so frequently?!

[dementedpixie]

You don't need to weigh as frequently as that and it's usual for ups and downs and plateaus in weight gain. He sounds fine and bf is obviously going great so well done