Long bone measuring short at week 36 us 😭☹️

I went in to my usual prenatal appointment today and my gyne suspect baby is achondroplasia due to femur length measuring 31 + 3 weeks at 60.5mm which is less than 1st percentile. However, baby's head measure normal which is exactly 36 weeks, and abdominal at 34 weeks. Only femur way behind 😭 I'm so worry that I cried as I talk to my baby that he is the only child I will have (FTM and will be last as I'm 41 next year). Anyone have the same scenario which turn out that baby is actually fine and not achondroplasia?