Biliary Colic: Given the location of the pain (right upper quadrant) and the cramping nature, biliary colic is a strong consideration, especially if the patient has a history of gallstones or has recently eaten a fatty meal. The timing relative to her last menstrual period (LMP) could also suggest a hormonal influence on gallbladder function.

Gastroesophageal Reflux Disease (GERD): Although the patient denies nausea and vomiting, GERD can sometimes present with upper abdominal pain, especially if it radiates to the back or is exacerbated by lying down.
Peptic Ulcer Disease: The absence of nausea, vomiting, and fever does not rule out peptic ulcer disease, as some patients may present with pain only.
Hepatitis: Although less common, hepatitis could present with right upper quadrant pain, and the absence of fever does not exclude this diagnosis.

Cholecystitis: An inflamed gallbladder can present with right upper quadrant pain and may not always have fever or nausea. Missing this diagnosis could lead to severe complications, including perforation.
Pulmonary Embolism: Although the pain is in the right upper quadrant, pulmonary embolism can sometimes refer pain to this area, especially if the embolism is peripherally located. The absence of respiratory symptoms does not exclude this diagnosis.
Appendicitis (with atypical presentation): While appendicitis typically presents with right lower quadrant pain, atypical presentations can occur, especially in women, where the appendix may be retrocecal or retroperitoneal.

Hepatic Artery Aneurysm: A rare condition that could present with right upper quadrant pain due to rupture or impending rupture.
Right Upper Quadrant Mass or Tumor: Although rare, a mass or tumor in the right upper quadrant could cause pain, especially if it involves the liver, gallbladder, or surrounding structures.
Intra-abdominal or Retroperitoneal Hemorrhage: Spontaneous bleeding into the abdominal or retroperitoneal space could present with acute pain and might not always have obvious causes like trauma.