I Was Lifting, Specifically Doing Dips, About Two Months Ago

I was lifting, specifically doing dips, about two months ago and felt a pop in the middle of my chest followed by a stabbing pain for the next days. Since that day my chest randomly hurts in the full middle area of my chest when I stretch above my head. I also recently noticed a small indentation in the top middle of my chest where some of the pain is, that indentation never use to be there.