A running stomach means diarrhea and yes that can be a sign of pregnancy but is not a particularly common one.
Is Stomach Cramp And Running Stomach A Pregnancy Symptom?
I have not understand by running of stomach. If you means palpitation in stomach then it is not a signs of pregnancy. All signs of pregnancy in humans are not reliable because many other conditions can also cause this. Most common signs of pregnancy are
1. Missing of periods on due dates
2. Nausea
3. Vomiting
4. Breast tenderness
5. Frequent urination
6. Fatigue
7. Headache
8. Heartburn
9. Fainting
10. Constipation
11. Food cravings
12. Backaches
1. Missing of periods on due dates
2. Nausea
3. Vomiting
4. Breast tenderness
5. Frequent urination
6. Fatigue
7. Headache
8. Heartburn
9. Fainting
10. Constipation
11. Food cravings
12. Backaches
Only stomach cramp can not indicate pregnancy because stomach cramp is not necessarily due to pregnancy as many other conditions can cause this. You should not rely on the any symptom of pregnancy because non of them are reliable. If you are suspecting pregnancy then get pregnancy test after missing of periods on due dates.