Arm pain

I started taking the pill just this last Sunday and over the course of the last 2 days, my right arm has had this strange pain. There’s no signs of swelling or redness. It feels slightly numb down near the elbow and has just grown very weak. It’s stuck in that feeling of hitting your funny bone. The pain sort of out from the elbow all down and up my arm and there’s also a pain in my back. And I may have a swollen lymph node in the armpit of that same arm. I don’t know if I should be concerned or what I should do for it. I’m slightly worried a blood clot could be forming but I’m not all that sure. Has anyone else experienced this?