An Oncologist is usually the last step in the process. It's tests and diagnosis, biopsy, additional surgery as recommended and if malignancy is found then Oncologist. I would think seeing a Breast specialist would be an appropriate next step for you at this point. You didn't state what steps you have already taken up to now. Wasn't something advised after your diagnosis ??
What were the specific findings? What type of biopsy did you have? Were you not referred to a specialist after your atypical hyperplasia was found? Were you given a come-back-in-six-months recommendation? With your family history, your doctor should at least bring up the possibility of lumpectomy or excisional biopsy.