Baby girl is measuring small

Has anyone else been through this? I’m 31+4 days and had a ultrasound at 30 weeks due to being high risk because of my age and hypothyroidism. She was only weighing 2.15 lbs , still in the normal range at 32%. But at 24 weeks she was in the 47%. Doctors are concerned about the numbers dropping and have me scheduled in a couple of weeks to check and make sure she doesn’t fall under 10% and have Fetal Growth Restriction. Has anyone been through this and delivered a healthy baby?