I got mine a week and a half ago. Day 2 was worse. I think they do it in dominant arm so it hurts less since you use it more. That's what my dr said. If that's true, glad i didn't get it on my left!
I got mine last week. The first day was a little sore, but the second day was the worst. I regretted getting it on the right arm since I'm right handed and need to move my arm a lot. The third day, however, I had barely noticed it. You should only have the pain for a little longer.
Got mine a few weeks ago. Gently stretch your arm for the next few days and it will help reduce the pain.