baby breath smells like poop

Hi mommies, I noticed the breath of my 7months pld baby boy last week na parang foul smell sya. Nung una para syang metallic smell, hanggang sa parang lalong bumabaho, minsan nag sstay yung smell sa pacifier nya pag tinatanggal ko ksi inaamoy ko. Just now prang mapanghi na kaamoy ng poop nya. Im so scared, akala ko nung una normal lang ksi he’s teething, pero nag search ako.. is there someone na same case sa baby ko? Please give me advices. Thank you. We are planning to go to his pedia na kaso nsa out of town pa. Maybe patingin ko muna sya sa iba