Is it fine without going to the doctor for three days straight with a fever?

It depends on the temeparture itself. One day of 40°C is very dengerous for young children, but minor fevers aren't real problem. It might just be a little virus passing by.

The only thing that matters is wether or not the situation gets worse, what are the others symptomes and if new symptomes are appearing.


Anyway, if you think things are going wrong, do not hesistate to see a doctor.