Thank you for your query at DoctorSpring.com
I understand your concern.
Your symptoms are suggestive of gastritis ( pain in the epigastric area, getting referred to the shoulder blades ), mostly indicates an ulcer.
So, the assessment by your doctor is right.
As of now, since ultrasound is normal, you need to get an UGI scopy done to confirm the presence of the ulcer and assess the severity.
Also, you can start taking Cap. Omeprazole or Prilosec twice daily till the tests are done. Probiotic supplements will help with the bowel movements.
Please feel free to discuss further,