I AM 46 YO WF WITH MILD PAIN THAT COMES AND GOES IN THE UPPER RT TOWARDS CENTER OF CHEST , IT ONLY HURTS WHEN I BREATH, IT WENT AWAY FOR 2-3 DAYS, BUT HAS COME BACK. I M AFRAID OF MAYBE BLOCKAGE OF SOME KIND, WHAT DO YOU THINK, COULD IT BE A PULLED MUSCLE, I WAS WORKING OUT MY RT HAND TO STRENGTHEN IT ABOUT A WK AGO, BUT NOW I DON T THINK THAT S IT SINCE IT HURT, THEN QUIT AND CAME BACK?