I have had intermittent left chest pressure for a few days.  I have had this feeling briefly on occasion in the past, but it seems more frequent in recent days.  Low energy seems to go with it.  I know there are things non-cardiac that can cause these symptoms, but how can I tell the difference.  I plan to call and make an appointment, but does it need to be a "now" appointment, or just for a physical?
You need to get an electrocardiogram and a 2Decho done. It seems you have a cardiac issue and it would be better to get it evaluated without delaying.