For a week or two, I experienced a dull pain on my lower abdomen and this pain spread to the lower back (pelvic region) with a warm sensation. Stone?

Unlikely. Stone pain is excruciating, tends to radiate from flank to groin. Would wonder about ruptured ovarian cyst which would be more likely to cause this type of pain. Endometriosis would also be on the list as well as a host of other diagnoses. Best to see your doctor for evaluation if symptoms persist. Hope this was helpful. Best of luck. Dr R.