Baby measuring small

My last ultra baby was measuring 11% percentile

Im now supposed to be 34 weeks and he has dropped to 6% percentile and two weeks behind putting me at 32 I’m at a high risk pregnancy now . They said I am very healthy no health issues no blood pressure no diabetes nothing ! And he is heathy and has good heart rate and very active . If nothing has changed by Monday when I go back u will be induced ..extremely worried this is my first baby

Could it be Down syndrome? They never did the test to check for it . Or something else? They also said I’m very small so it could just be a small baby his dad was only 5pounds when he was born