0.34 papp value

[pv72]

Hi, I'm now 14 weeks pregnant, I had test for down syndrome before a couple of weeks and found everything normal in scan, nt and hcg values were also normal but papp was 0.34 which is low, it must be more than 0.5 itseems. My doctor said no other special test is needed, just increase protein intake otherwise baby will be little smaller in size. My question is will protein intake increase this value? And is there any other test at later stage to ensure that my papp value is increased? It is common to have healthy baby with this low papp??