Small baby

Hello all. Had more scans yesterday to measure baby, she's 1.5-2 weeks small. Did more blood work to rule out any infections, was asked to do amnio and I refused, have to go back to see if she's at least grown a week before we move on to anything else. :/ I'm hoping it's just genetics and I make small babies. I should be 22 weeks today but baby measured at 20+6. (20+5 yesterday) she was super wiggly in the ultrasound and even when the doc came in, they all said she's very photogenic. Just hoping next appointment she has grown at least a week. Anyone have that experience and go back and all be well?