I can understand your concern and hope you are not in too much pain right now.
The pain you have mentioned but you haven't mentioned the exact site.
Is it on the right side or left side?
Is it in the middle, upper part or the lower part?
Different areas on the abdomen pain due to different causes.
To tell a specific cause you should have given a little more details.
Gastritis, constipation, renal stones, gall bladder stones, abdominal infections can all cause pain. To tell you your cause, you need to give us a detailed history and also you need to be examined clinically.
Suggest you to meet a general surgeon in person for further help regarding this issue.
Dr. Anil Kumar Jain.
There are so many causes for pain in right side of stomach
1. Due to gastritis or appendicitis or food infections .
So you have to consult a general physician , they will give treatment .
You can use tablets given by them for 5, days.