Hugs hun, baby is very well protected and snuggled up inside, very unlikely that Zak could hurt baby and cause a mc.
DS1 has always been a wiggly boy and my belly was often kicked or hit as he was climbing on or off me or when being changed and DS2 is fine.

I know the stress as my first preg was a mc too and through both subsequent pregnancy's I was very worried!

Hugs rest up and take it easy