Please be reassured that your symptoms are very common and highly unlikely to be signs of breast cancer. Breast heaviness before your period (cyclical mastalgia) and back pain during menstruation are typical responses to normal hormonal fluctuations. To relieve this pain, over-the-counter options like ibuprofen, naproxen, or acetaminophen are highly effective. For breast tenderness, topical diclofenac gel or evening primrose oil supplements can also help. Wearing a supportive, well-fitting sports bra during this week is also beneficial. If you notice any new breast lumps, skin changes, or if the pain persists, please consult your doctor for a personalized evaluation.