Morning spit up (clear hours after feeding)

Every morning once the sun comes up, DS wakes up in his crib and doesn't sleep as deeply. So I usually pull him into bed with us so that we can all sleep a bit longer. What I have noticed now is that a couple of hours after a feeding in our bed, he will spit up clear fluid. Almost every morning this happens. I lay a burp cloth down under his head to catch this, but I am wondering if this is something to be concerned about. His crib is slightly elevated and I know he doesn't spit up in there because when he spits this clear fluid up, he usually gets pretty upset about it. 

Any thoughts please?