No, it is not safe to receive a diclofenac injection right now. Both piroxicam and diclofenac belong to the same class of medications known as NSAIDs (Nonsteroidal Anti-inflammatory Drugs). Taking them together or too close together does not improve pain relief; instead, it significantly increases the risk of side effects like severe stomach irritation, acidity, or kidney strain. Since you took the piroxicam tablet only an hour ago, please do not take the diclofenac injection. If your period pain remains severe and unmanageable, please contact a healthcare professional or gynaecologist immediately to discuss safe alternative treatments.