Hello.
I used to have very sore breasts when on a pill (microgynon) with too much estrogen in it.
After three months they were still very tender so I changed pills. Usually the side-effects should be gone after three months.. if not, you can decide whether to change pills or not.
I have changed to a low-dose pill and still have sore breasts most of the time. My doctor suggested taking vitamin B6 supplements... I am trying those, but I am not good at remembering to take it more than once per day.. but I think even that is helping a little.
I would wait and hope it gets better over the next month or so...