What are the signs for an over protective dog or is he just jealous?

I HAVE A ROCWILLER AND A 7TH MONTH OLD BABY THAT IS ON THE GO AND MY DOG TENDS TO GET ANTSY. WHEN SHE CRIES HE LEAVES THE ROOM. BUT IF SHE SLEEP OR WHERE OUT WALKING HE IS VERY PROTECTIVE HE WON'T LET FAMILY IN THE ROOM WHILE SHE SLEEPING AND WON'T LET YOU GET WITH IN 5 FEET WHEN OUTSIDE. I WANT TO KNOW IS THIS GOOD OR SHOULD HE GO NOW?