Throwing up in the morning

Hi, I am a 20 year old male, and in the mornings I get a lot of phlegm. And sometimes after I spit this phlegm out it causes me to gag very heavily, leading to my body to throw up. I don’t feel sick, or nauseous, I feel perfectly fine but for some reason I keep throwing up following me spitting phlegm out. It doesn’t occur every morning, but it is at least 3-4 times a month. Does anyone know what could be causing this? Thanks.