Hello dear,I understand your concern.In my opinion primolut N doesn t result in preventing pregnancy.As you have irregular cycles the causes of irregular cycles like PCOD,thyroid abnormalities,stress,overweight or obesity need to be evaluated.If overweight or obese weight reduction itself helps in regularisation of cycles.Ultrasound and thyroid profile might help in diagnosis.So consult doctor for diagnosis and apt treatment.Once the cycles get regular the pregnancy chances will increase. Best regards...Dr.Srilatha