Sore spot on right side of my breast but no lump. it couldn't be breast cancer right?

No guarantee: Breast cancer is not always readily palpable. Can include a mass. Masses that are painless, irregular ; hard are more suggestive of cancer but they can also be tender, painful ; soft. Swelling of breast; thickened, red, skin; non-milky nipple discharge; new retraction of nipple, puckering or irritation of skin or pain ; sometimes swollen lymph nodes under arm(s). Seek med eval if you have sxs.