Weight gain concern - reassurance required please

[Booper13]

DS3 is 21 weeks and has been ebf. He was 6lbs6Oz and has been between 9th and 25th percentile until he was 3 months. He then had a dip and continued along between 9th and 2nd. When I got him weighed yesterday he is below 2nd and had only gained 9.5Oz in 5 weeks. He is now 12lbs9Oz. The HV at the clinic said she would "refer" this to my HV and he may have to see GP. He has been feeding ok - always short feeds, but quite frequent day and night. Never more than 3 hours between feeds. I think (am pretty sure)I have enough milk but after 5 mins or so he doesn't want any more. I often offer him and he's not interested. He is a v happy, content baby with lots of wet and dirty nappies (about 4 poos a day). He is def not skinny in spite of percentile drop. Over the last couple of weeks he has been a bit sick after feeds - not lots and doesn't seem bothered by it.
DS1 and 2 were always around 9th and to put it in perspective I am only 5 feet and 7.5 stone (or was pre birth...those were the days). DH is smallish and has a slim build. They mentioned weaning, but I really don't think he's hungry - showing no signs of this so I don't feel food would help. Ditto bottle of formula. What do you think.
Thanks for all advice.

???

I wonder why the HV has referred him. The usual guidance is that a drop of two centile spaces is on the normal spectrum, and it's only beyond this that a medical opinion is needed. Maybe your HV is taking it as a drop from 25th, to below 2nd, and as such feels he falls within this 'referral window'.

The vast majority of babies who drop more than 2 spaces are actually fine but the research shows that a referral is clinically justified to pick up the ones who are not - these would be the ones where there might be some rare disorder not yet spotted (highly unlikely in a baby of 21 weeks with no other signs) or who are actually poorly or where there are other social/emotional problems with the family. So the HV you saw may just be obeying local protocols for referral without really thinking anything is 'wrong'.

If it's thought your baby could do with extra calories then of course you have them - in your breasts :) If a mother is happy to feed more often (maybe offer him more 'sides' each time as well as offering more feeds) then it makes no sense to give formula or solids. Formula does not have more calories than breastmilk, and many early solids have fewer, so it would be a bit daft to do anything other than simply bf more often - if it's thought your baby needs more to eat :)

Thanks tiktok. I guess I'm just a bit worried. My instincts are that he is fine. I do offer both sides, but generally he only wants one. I can put my boob in his mouth, but can't make him drink!
Presumably if he was hungry or not satisfied he would be crying/unsettled? Is this the case? He is neither, just seems not to have a huge appetite. Are there any tips on how to get a bf baby to drink more. (I have DS1 aged 4 and DS2 aged 2 to consider too so can't spend all day just trying to feed).