Joni, I've never heard of this type of vibration you describe as being a sign of breast cancer. Only your doctor can make this determination -- and any diagnoses -- for sure. Breast cancer isn't usually something you "feel" - except that you may feel a lump. Other than that (and unless it's inflammatory breast cancer, which is painful and hot), it doesn't feel like anything. If it continues to bother you, by all means get it checked out; being on the left side, maybe it has more to do with your heart than your breast? But whatever, to set your mind at ease - make an appointment to see your doc, OK? Good luck - PJH