Constant dull pain in right lower abdomen been to Dr multiple times?

For a month or two now iv had a dull pain in my lower abdomen right and below of my belly button. The pain seems to come and go. Its a dull crampy pain it almost feels like gas but has been going in way to long. It seems to all have started after having a UTI and the only symptom I had when I had the UTI was the same feeling. I was treated and tested for STD ( all negative) and went back and tested again and UTI was gone. Just wanted to see if anyone had a similar experience or any idea as the Dr seems to not know other then possibly a kidney stone. But the pain not that severe just more of an annoyence