I WAS JUST DX'D WITH A UTI. I DON'T HAVE

I WAS JUST DX'D WITH A UTI. I DON'T HAVE THE USUAL SYMPTOMS, NO BURNING NO RUNNING TO THE BATHROOM, MY PERIOD DID NOT SHOW UP. I HAVE HAD SHARP PAINS ALL OVER MY TORSO AND UNDER MY ARMS FOR ABOUT 2 GOOD WEEKS, TIRED FEVERISH. SOMETHING WAS GETTING LARGER IN MY RIGHT SIDE BEFORE I GOT THE ANTIBIOTIC. IT SHRUNK TO HALF THE SIZE AFTER THE FIRST PILL. then my period started. NOW the thing in my right side IS LARGE AGAIN AND HARD. WHAT MIGHT IT BE?