I would find another doctor, if all is OK, then, I would see a chiropractor, you could very well have a pinched nerve in that area causing the pain.
I have had this issue as well and I ended up having my gallbladder removed. Go & get a gallbladder function test or/& a ultrasound of your gallbladder. Also having excess gas build up can also be causing this pain. When I had it I was told to take some GasX. Then it ended up being my gallbladder.
Good Luck
I too have experienced the pain u are experienceing i havent gone t o the doctor but have looked on the internet i too had a baby a year ago n breast feed and still am so whta u could have is mastitis which is a bacterial type of thing common in women who have breastfeed even only for a while u may have got bacteria in ur breast dont worry its not serious but maybe if u mention it to ur doctor as a possibilty he could properly diagnos u and by the way it usually only appears in one breast. So there is a good possibility u have this i may even have it. well i hope this helps u out.
Find another Dr. There's something going on and your current Dr sounds like he's not willing to help.