What Causes Bruise On Abdomen After Taking Prolia Injection?

I received a Prolia injection yesterday for the first time and this morning I noticed a skin discoloration on my abdomen. I looks like a bruise but I know I did not injury myself. Should I be concerned and call my doctor? It does not appear to be an infection it just looks like a bruise. What a scam. Pay for an answer. Here I thought what a great service. I can help myself thank you. Have a nice day.