I had a painful lump in breast last night. could this be a symptom of breast cancer?

See a doctor: Most painful breast lumps occur around the time of the menstrual cycle and are benign fibrocystic nodules. However, all new & concerning breast changes must be examined by your doctor & will likely need mammogram and possible breast ultrasound evaluations.

See a Doctor: Any new, persistent lump in the breast should be a cause for concern, best handled by seeing your gyne or primary care doctor. While most cancers are not painful, it is not a reliable finding. Hopefully, your doctor will be able to alleviate your concern or refer you to a breast center/surgeon for definitive evaluation. I hope its a false alarm--good luck.