There are so many different ailments that can cause the symptoms you’re describing, that not only would it be reckless to try to diagnose you via chat room, but likely even when you do go to your doctor and he will give you a few possibilities.
I would highly recommend that you don’t try some of the ideas above, because some of them can actually kill you, depending what the actual ailment is.
For example, what you were describing can be the symptom of a heart attack. In which case taking aspirin might help.
However, if it is an ulcer, then aspirin might cause you to die from internal bleeding.
If you’re looking at some of the more simple solutions like taking Coca-Cola(drink it flat), or taking Tums, that may help a lot assuming that it is simply an upset stomach (of any variety) or acid reflux.
In short, if you are inclined to think that it is not something massively serious, then take some thing over the counter. However, since you seem to be indicating that these are new symptoms for you, you probably should go check it with the doctor.
Regardless, keep us posted as I’m sure many of us are morbidly curious.