My ds had 2 positive cases in his class last week so we were asked to test the children each morning before school. On Friday my son had the faintest T line ever, so much so that it couldn't even be seen in a photograph when I tried to take a picture, only in the right light could you see it and it only popped up in the last 5 minutes of the 30 min time frame. He had no symptoms but we kept him off anyway. We tested him on Saturday -negative, tested him this morning - negative and still not one single symptom. Does he even have it? We've all had covid before with symptoms including the children back in November so we've seen his body's reaction to this virus before, he's completely well!