Hi, Thanks for sharing your health concern with us. In the current scenario, as ovulation cannot be predicted, home pregnancy test may not be much useful. HPTs read well when performed 3-7 days after the missed period with a fresh early morning sample of urine. For an earlier and better confirmation, estimation of the serum beta-hCG titres is needed as this is more specific and also sensitive. Since you have a history of irregular periods, if pregnancy is excluded, you should be evaluated for hormone imbalances and treated accordingly. Duphaston is unlikely to cause the menstrual aberration you are experiencing now. Please go ahead with further evaluation. Take care.