Dear Shelbysmom: It is not uncommon at all for breast to feel lumpy and bumpy, particularly in the younger years. The purpose of regular breast examination is to identify changes in the way the breasts feel. This is why the recommendation is to check the breasts once a month at about the same time (after the menstrual cycle, for example). Hopefully, by becoming familiar with how the breasts feel, a change would be easier to identify. If the doctor is unable to detect a lump, it may be that you are indeed feeling a rib - this is not uncommon in young women.
When women are younger, the breast tissue tends to be quite dense. Mammography may not be the best test to use for dense tissue. If there were a lump or need for further investigation, diagnostic breast imaging (with mammogram and/or ultrasound) may be a recommendation. Given the doctor's findings, 3 months may be a reasonable wait for reevaluation - knowing that in the meantime if there were any changes, you could be seen sooner. Screening mammograms are of unproven value in women under the age of 40, however, in high-risk individuals screening may begin earlier. It may be worthwhile for you to undergo formal risk assessment and receive recommendations from a breast specialist such as the one your mother sees in her high-risk clinic.
I just wanted to update that I requested that the doctor go ahead and order me a baseline mammogram and she agreed to do so. Thanks so much for your response.