Tiny baby??

[needzadvice]

So I had an ultrasound at 28 weeks for complications with consistent protein at +3 in my urine my entire pregnancy and because I haven't gained but actually lost weight so I started at 120 lbs pre pregnancy and am 30+3 and am 109lbs today so anyways I haven't gotten full results till the 19th but was already schedualed for another ultrasound the 18th because he is looking quite small!!! I've never had them say this before this is baby 5 for me 1 boy and 3 girls so far my biggest was 8,13 and my smallest my last was 6,13 and I was never ever told she was small. I'm worried my placenta may not be functioning well but won't know more till my next scan on Monday and then get actual answers at my dr apt the 19th so im super nervous I don't know what they do for him or what sort of plan is in place . If he hasn't grown from the last scan will they take him early? My Dr has told me I may be hospitalized for my malnutrition from constant puking and nausua but hasn't given me any sort of end goal! She told me they don't chart babies growth till 30 weeks so I know that's why she waited to get me for another one but if he's already measuring small at 28 weeks isn't that still bad? Is there certain guidelines for babies like what is considered small and what sort of complications can come with this? I've never had a c-section or a baby born early so I'm orally freaked out!!! Has anybody gone through this or can give me any insight on what's to come! Please Id be sooo greatful ! Thanks for reading my long winded post ladies :)