What Causes Pain In The Upper Stomach?

For the past 5 or 6 days I've had slight pain/cramping in my upper stomach. It comes and goes throughout the day, with the pain lasting for 5-10 seconds. It's far from unbearable and antacids seem to be working. However, the cramping is most prevalent when I have an empty stomach. I've been testing different types of foods to see if they have an impact on the symptoms. So far the only thing that seems to cause the discomfort is an empty stomach.

The pain itself hasn't really impacted my daily activities and never reaches a point where it's too much to handle. However, I'm somewhat concerned because I've never had this problem before.