When taking Cycloreg (Norethisterone) to delay your period, some women may still experience breakthrough bleeding or spotting, which can be heavier and accompanied by cramps. This happens because:

• Hormonal fluctuations: Norethisterone alters your natural hormone cycle, but your body may still partially shed the uterine lining, causing bleeding.
• Timing and dosage: Starting the tablet close to your expected period date might not fully suppress the period, leading to bleeding.
• Individual response: Each person's body reacts differently to hormonal medications, and some may experience side effects like heavy bleeding and cramps.

If the bleeding is very heavy, prolonged, or accompanied by severe pain, it is important to consult a gynecologist. They can evaluate for other causes such as infections, hormonal imbalances, or other gynecological issues and adjust your treatment accordingly.

Meanwhile, avoid stopping the medication abruptly without medical advice. Keep track of your symptoms and any changes to discuss with your doctor during your visit.