Recurring dream or nightmare?

Sometimes when I am dreaming - I feel like I am either trying to get up or wake up, and it feels like someone or something is pushing down on me. Almost like smothering me and when I finally do wake up, I wake up scared and looking around to see that nobody has actually come into my room and try to actually assault or smother me in my sleep, normally I don't pay too much attention to dreams. But this is a dream that has happen enough times for me to remember it.