Sever abdominal pain and cramping in the lower abdomen moving to the right side & under the ribs and causing sever pain in the shoulder nausea no bm?

Gallbladder attack?: It sounds like a gallbladder attack from a gallbladder problem such as gallstone blocking the common bile duclt. It can be appendicitis but it is less likely. Go to ER to be taken care of promptly.

Severe abdominal: pain warrants urgent medical evaluation.

See a doctor: Severe abdominal pain and nausea can have many causes. Depending on how long it has been since you had a bowel movement, it can be something as simple as constipation. However the differiential diagnosis alsincludes appendicitis, a ruptured ovarian cyst, an ectopic pregnancy and severe pelvic inflammatory disease all of which need immediate attention. Go to the ER now.