What could be the cause of spitting brown phlegm in the morning? After a couple spits it's clear and doesn't do it again till morning. No blood when I blow my nose

Need diagnosis. Brown phlegm is probably not from the oral cavity or from the gums. Obviously, you need a proper diagnosis. Although you say there is no nasal bleeding, i would worry more about old blood coming from the esophagus or stomach. An ENT doctor or a gastroenterologist should be consulted.