Lump

Hi 

I have just found a hard lump under my left breast - sitting on the bra line. It's not normally there but not directly attached or underneath my breast so should I be worried. It's uncomfortable and a little sore to the touch. Obviously in this lockdown situation, doctors are closed for normal apts so don't know whether to just leave it a few days and see if it goes away  - just wondered if anyone had, had anything similar and could give me some advice - I'm probably just Over thinking but wanted to ask - thanks