How do you stop your breath from smelling after eating mussels?

My girlfriend claims that my breath still smells after I had brunch with my parents and I ate mussels as my meal. She tends to have a really good nose (insanely good), but I've brushed my teeth (and tongue) multiple times as well as eaten several mints and I even have taken a shower since brunch. My breath doesn't normally smell so is my girl just crazy or could my breath still smell? If so what should I do?