Diagnosed acute pharyngitis, 12 days since, fever gone, sore throat gone. Still red spots roof of mouth, white tongue remain. Should I be concerned?

No. Acute pharyngitis is usually a viral infection. I wonder if your PMD put you on an antibiotic. If so, the white tongue could be a fungal infection. Red spots on the palate still could be the viral infection that persists. Do not be concerned, but if the spots persist see either your doctor or a specialist in oral medicine.