Arm pain after IV was installed

I had a stress test done over a year ago. It took a few tries to get the line installed in the bend of my arm. The line was in my arm for about an hour while I was being tested. It hurt the whole time it was in, which I know now isn’t normal. The next day my arm was black and blue where the line was installed. Since then when I try to bend my arm to make a muscle, the pain will only let me bend it half way. It feels like there is something in the bend of my arm. There is nothing visibly wrong with my arm. I would like to know what’s wrong.