Yesterday i found a lump on the inside of my lower right breast its kind of hard and my entire breast is hurting im 18 im scared! is it cancer?):

UNLIKELY: What you are describing is most likely fibrocystic changes. These are common among women. Breast cancer is very uncommon in your age group, and usually presents as a firm, non-tender mass. Now, you still need to see your doctor, who can help you manage the symptoms of fibrocystic changes. For now, take some Aspirin or Ibuprofen for the discomfort, which will probably change with your cycle.

Doctor follow up: It cold be an infection or cyst. I highly recommend that you haven't examined to confirm that it is benign. Based on what the doctor sees he may consider a biopsy to rule out cancer.

Probably not: It would be exceedingly rare for an 18 year old to develop breast cancer. Could be an infection or a cyst. You should you see your friendly primary care physician and let them know of your symptoms.