My wife is taking clomifene citrate(100 mg) tablet from the 2nd day of the menstrual cycle but she has been advised to take Duphastone on the 21th day of the cycle, if she didn't conceive could she repeat this therapy again? she has poly cystic ovary and taking metformin 500 mg regularly, two test TVS and HSG already done and no abnormality found, Please suggest.