What Causes Fluttering Feeling In Chest?

I have this flutterin feeling in my chest that makes me cough. It happens 5-10 times a day and has just started within the last week. Is this something I should be heavily conserned about? Can it wait for me to make a dr apt? I live on an army post and the dr are typically very busy and you can t be seen for a few days or even weeks. I ve had an issue with pain in my chest before and was hospitalized for a few days. What was happening is every time I would go from laying down to sitting up my blood pressure would drop causing me to pass out. Idk if that helps any or has anything to do with my latest issue.