A 25-year-old woman presents with a sharp lower abdominal pain that started suddenly earlier in the day. The pain is primarily on her right side. She reports that her last menstrual period was 6 weeks ago, which is irregular for her. She denies any vaginal discharge, fever, or urinary symptoms. What are potential causes and the next steps?
Given her history of a delayed period and sudden onset of unilateral lower abdominal pain, the main concern is an ectopic pregnancy. Other possibilities include ruptured ovarian cyst, appendicitis, or pelvic inflammatory disease (PID). The immediate next step would be to perform a pregnancy test. If positive, an ultrasound should be performed to evaluate for an ectopic pregnancy. If negative, the other differential diagnoses should be explored with appropriate tests and imaging.