Acute onset sudden severe pain radiating towards pelvis can be due to multiple causes as acute appendicitis renal or ureteric colic. U didn't mention other symptoms fever loose motion burning micturition vomitings and which side of pelvis you are feeling pain .
Next Steps
you need urgent ultrasound whole abdomen and baseline blood investigations and routine urine tests to establish the diagnosis and cause of pain
Health Tips
take safe painkiller as tab Drotin one tab twice daily for pain relief and immediately visit a surgeon nearby