Has anyone had this happen?

Shannon

Had my 16 week appt with ultrasound yesterday! Everything looked great except baby had one hand covering his/her face the whole time and wouldn’t move it. Baby was moving both legs and one arm but the other just stayed right in front of baby’s face. Is this normal? Or could this mean something is wrong with that one arm? I’m sure I’m overthinking things but just thought I’d ask on here. Any input would be greatly appreciated! Thanks!