Mucus in stool

Veronica

My 2 month old pooped right before his doctor walked in the room. As she was assessing him she opened up the diaper and saw that it was green and all mucus. She asked me if his poops are always like that, I said no. She tested the poop on Friday for a milk protein allergy and today the results came back negative. The online nurse said someone in the office will call me back with further instructions. Has anyone else gone through that and be something else?