why leaves turning yellow, do i have spider mites

well this is my 3 weeks old plant and the problem is some leaves are turning yellow and when i put it under the cfls i can see these tiny white dots on the top of the some leaves but when i take it out of the grow box i cant see nothing?????
looked under and all over for the spider mites but didn't find any, not sure do i have them idk am i being paranoid

if you zoom on the 1st or 2nd pics then the white spots are visible
idk what to do

Usually can mean mites look under the leaves is there little specs or little spiders.

yes i can see little things but how visible should they be to my eyes would i be able to see them clearly if concentrated and what colour because just spend 1 hour examination my plant but dont even know what i am looking for.

Take your thumb and gently rub the bottom of your leafs you see little spots on. If there is a green streak on the leaf or your thumb you have mites.
They are smaller than a grain of sand green and move if you watch them.

i just did that and nothing, i have been staring at it now but i dont see anything that could resemble a mite just black bits idk soil maybe, i have just sprayed it with water just got to wait and see right?