Hi Doctor. My daughter is 19. She has a sever sore throat. Hurts to swallow and her glands on neck are swollen. She has fever and is very fatigued. Says she feels like she has phlegm all over throat. we just discovered a red rash in the back of her neck and a little on her cheek . She tested negative yesterday for flu, strep and mono. I feel like it can still be strep or mono. Should she get re-tested?