9th Percentile at 20 Week Scan

Has anyone gone in for their 20 week anatomy scan and been told baby is measuring small, below the 10th percentile and later all was well? First time momma here and we had our scan yesterday and was told anatomically everything was looking good, including blood flow, but baby measured in the 9th percentile which Dr said we needed to monitor closely. We are going back for a follow up growth scan in three weeks but I’m looking to ease my constantly anxious mind while we wait. Already incorporating more protein and fluids into my diet, but baby needs to grow!