Hi.
Thanks for your query.
Noted the history and understood your concerns.
Indigestion along with
constipation, lower back ache and cramps are indicative of intestinal problems like colitis or so and not related to pregnancy and your tests are negative.
I would advise you the following in such a situation:
Get a stool test and send the blood for the tests of CBC, widal for typhoid, liver function.
If there is an evidence of infection your Doctor will start you on appropriate antibiotics and supportive medications like probiotics and symptomatic treatment for the cramps in the form of antispasmodic like Dicyclomin.
Also take activated carbon tablets, curds and bananas.
Watch for the foods and beverages that increase the problems and avoid such things.
Take plenty of oral fluids and electrolyte solution to avoid
dehydration and
electrolyte imbalance.
If the constipation persists your Doctor may advise you a
stool softener or advise to increase fiber intake.
Rest of the treatment will be as per the clinical evaluation and investigations.