For acute knee pain that started three days ago, you can try over-the-counter pain relievers. Acetaminophen is effective for pain relief, while nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can help reduce both pain and inflammation, provided you have no stomach or kidney issues. A topical diclofenac gel applied directly to the knee is also a safe, targeted option. Additionally, practice the RICE method: Rest your knee, apply Ice for 15-20 minutes, use a supportive Compression bandage, and elevate your leg. If the pain is severe, you cannot bear weight, or you notice significant swelling, please consult a healthcare professional for a physical evaluation.