26 week ultrasound measuring small

Alexis • 👩‍👦 Mommy to a wonderful, smart, handsome 13 year old. Trying for 🌈 baby

They told me everything looks good but want to see me again in 3 weeks to monitor growth. Say she’s only in the 11th percentile. Anyone ever had this? Say they usually don’t worry unless it’s under the 10th percentile but that really close. Also she was measuring a little ahead at 20 week scan.