As your ultrasound is normal,there will be no major problem.
If there is pain in the upper abdomen,it could be due to Stomach ulcer
.IT is relieved by Rabeprazole
If it is in the lower abdomen,Uterus,ovaries have to be checked.If they are normal in ultrasound,then urinary tract infection
has to considered.please take Levofloxacin
tablet along with Dicyclomine.
Even then,if you are not comfortable you can go for Diagnostic laparoscopy,where your abdominal organs will be visualised directly by key hole method .
If you come back with above test results, i will clarify further
Wish you good health