Thanks for your quick responses.

We are both on the small side of things so it could be genetic. I wouldn't worry so much if he was just cruising on a low percentile it's the issue of him continuously falling on the curve. I just wonder where it will all stop. I think what also increases my worry is that my family openly talk about how thin I was getting as a child and there was a point where they wondered if I would even see another year out. I literally was a skeleton as my coeliac disease was undiagnosed (a long story of inadequate GPs where we lived and little knowledge of coeliacs). They never spoke about this to me as a child but they do now as adults.

Currently his diet looks like this:

7am-ish - EBM (maybe about 130mls)
9am - 2 x weet bix with a bit of pureed fruit and maybe 50mls of EBM
12.00 - offer some EBM (usually will only take maybe 30 or so mls)
1.00pm - soy yoghurt with fruit. This will now be changed to meat and veg.
3.00pm - offer some EBM will only take a small amount
5.00pm - a big bottle of EBM
6.15pm - meat and veg
5.45pm - a small bottle of EBM
9.30pm - a big bottle of EBM

I'm on motilium so I do have a good BM supply. DS won't take anymore BM. The only thing I could do is get him up in the middle of the night. I used to do this up until 2 months ago as I was up to express anyway. His milk intake would probably increase maybe by about another 50mls if I did this. I stopped doing it as he is capable of sleeping through the night and it was one less night time activity for me to do. On my last visit to the paediatrician she told me that I could stop doing the middle of the night feed (he was on the 25th percentile for weight then).

Generally DS is happy and seems healthy enough (although we have a grizzly patch this week the nurse said it was tantrums) and generally speaking his development is on track a little ahead on some things like fine motor skills and a touch behind on gross ones.