HI IM 13 YEARS OLD, AND LAST NIGHT I HAD A PAIN IN MY LOWER RIGHT SIDE, UNDER MY RIBS, I WAS SLEEPING ON MY STOMACH, AFTER THE PAIN, I TRIED TO TURN OVER TO MY BACK, BUT WHEN I MOVED IT HURT VERY BAD, I COULDNT BREATH VERY DEEP BECAUSE IT HRT WORSE, WHEN I FINALLY GOT OVER ON MY BACK, THE PAIN FINALLY STOPPED. WHAT COULDTHIS BE ?