Baby not growing....

First, sorry if this is the wrong group, I’ve posted in several because I didn’t know where it should go.

So currently I’m 27 weeks pregnant and the baby is only measuring 23 weeks. All measurements have been on point except this one. The doctors are very concerned and want me to see a specialist. All tests came back fine. What could be wrong with my baby? Am I doing something wrong? Is there something else I can do to help the baby grow??

Please if you’ve gone through this before, I’d like to know how you went through it, did baby come out fine, what did you do.