Measuring Small?

LCrew

Had my 37w ultrasound and baby is measuring 35w/5d!! Smallest it’s every come in, around 5pds 7oz. At 31 weeks baby was 3pds 10oz... has anyone else had such an odd result ? Baby is in the 27th percentile which is low as you can tell. Hoping everything is normal and ultrasound tech didn’t get the right measurements. Not sure what to think- hoping I don’t go to 42 weeks