My 3 y old had tonsillectomy from 3 days now he has a white spot in his tongue. he is in the antibiotic from more than tonsillectomy week. so worry ?

Possible thrush: I hope your son is feeling better after having his tonsils removed. What you are describing could likely be thrush which is a yeast infection due to post surgery antibiotics. Your physician could prescribe nystatin, or You could try dabbing white distilled vinegar on it, or having him eat yogurt with active cultures. Some people also recommend probiotics to restore bacterial balance.