J.N.
If your ped isn't too concerned, then you shouldn't be either. Teething can be incredibly painful, especially the first ones to break through. My daughter pretty much refused to eat for several days when hers first broke through. However, as a mom, I understand your worries about not eating, even though the primary source of nutrition right now is via breast milk/formula. Try and offer her soft foods and try them cold/chilled as they may feel good on her gums (mine loved semi-frozen applesauce).
If you still have nagging doubts, then by all means, find a second opinion. Good luck and hang in there.