Talk to Gastroenterologist on Severe Abdominal And Stomach Pain

I have stomach acidity problem with abdominal pain before and during menstrual days from 6 to 7 months , I go to the doctors here, they give pain injection which makes a difference for a few hours, but I have this problem again and again. This time the pain is severe with mild fever . I feel pain like severe constipation or abdominal gas ,