2 year old tired, fussy, not eating...

Any ideas what could be going on? My 2 year old has not been himself for the last week or two. He won’t hardly eat, especially at supper, he end up crying and wants me to hold him. He wants to take naps... he actually asked to go to bed a few days ago. And he is very whiny and crying.... all of these are very uncharacteristic of him other than the occasional rough day of just being 2... he has no other symptoms of anything.... should I take him to the dr? Or is it nothing?