Does your newborn have sulfur smelling farts? Rotten eggs?

Stevie • Mom of 3.
I exclusive breastfeed. I also feed my 2 year old 6 times or more a day. He's a week and a day old... when he passes wind it smells rotten. :( His appointment is Friday so of course I'll ask the pediatrician. BUT I'M WONDERING, IS IT BECAUSE HIS SISTER IS STEALING HIS GOOD MILK? OR SOMETHING I'M EATING?