I found exactly the same on my left breast two weeks ago. I got an emergency appointment with my GP who referred me to the breast clinic at my local hospital where I was seen within 5 days. A mammogram showed 'something' there. This was followed by a scan and biopsy (all on the same day). After waiting about an hour for the result of the biopsy I saw a consultant who was happy to tell me that I had benign cysts.
I was overwhelmed by the prompt, kind attention I received. Whilst waiting for the result of the biopsy I saw some distressing scenes of young women who had received bad news. The one wo has stayed in my mind was a very young girl (17 at most) who was breaking her heart whilst her Mother tried to contain her own distress.
Our NHS gets some bad press but I have nothing but admiration for the dedication of the staff how I was seen so quickly and my mind set to rest.