Hi Shelly monolisa
I dont think the problem you have is related to cancer. Reason is that you dont expect a cancerous growth which was there in 2009 to disappear with antibiotics and reappear after 3 years. Most likely you are having an infection especially since Mammogram
is negative. Any way keep the lump under observation (without getting worried at all). If it is getting bigger in size then probably you would need a repeat mammogram and biopsy
confirmation. On the other hand if there is local pain or redness
( which could indicate infection) consider nearest physician to rule infection/ antibiotics.
Hope you are satisfied