The gold standard for diagnosing streptococcal infection is a microbial isolation by culture. At this stage, after having received antibiotics, the culture could be negative. Thus we cannot at this stage be certain that it was streptococcal infection since many other infections including viruses can give rise to pus points. If the child is improving and the fever has subsided, I would leave him alone. However, the best advise can only be provided after a clinical examination and/or performing relevant investigations.