Slight swelling under right armpit.

I have noticed a slight swelling under my right armpit. I don't feel any lumps in and around my armpits and breasts. It looks like it could just be muscles and tissue but it wasn't there before. It looks and feels slightly different than my left side. I have no pain in the specific region either. I got my 1st COVID shot (covaxin) on June 6th.. But on my left arm. I have read that it can sometimes affect the lymph nodes. Could this be a side affect? I work in IT and gave been doing WFH for more than year. Sedentary lifestyle has contributed to some weight gain as well. Could it just be that? I got some tests done before my covid shot and it was all good. I'm really confused and exploring all options. Do I need to worry about this? If yes.. which specialist should I consult for this?