No, I'd say that your Dr is just taking extra precautions in having an extra scan given that you lost a baby. Measurements can be wrong. Probably just wants to check that everything is fine for the delivery. If there was anything wrong, yes I'd think he'd have to tell you.

My Ob did extra scans because I lost a baby and had resultant medical problems that could have caused problems in any subsequent pregnancy.

Wishing you all the best.
TICKLISH