MOST breast lumps are discovered by accident, either during a shower, or while asleep or when there is breast pain. Pain seems to trigger a person to suddenly pay attention to their breasts. Ironically, pain is an uncommon symptom in breast cancer. Breast cancers tend to be silent and may not make you feel sick at all.
One lady actually only realised she had a large lump in the breast after being hit in her chest (her dog had jumped to greet her). She waited for several weeks, thinking it was just a big bruise from having been hit. It was fortunate she had a knock on her chest to bring to her attention the presence of her breast lump. Subsequent investigations showed this was a cancer!