Is It pregnancy?

Hi,
Welcome to ehealthforum,
If you are not pregnant, you should have had withdrawal bleeding within 10 days of taking the last dosage of Duphaston. The prescribed medication Duphaston does not cause any harm to baby/fetus (it is also prescribed in pregnancy for prevention of miscarriage). The symptoms that you describe (sore breasts, abdominal distension, low back pain, delayed periods, spotting/altered bleeding, dizziness, nausea, tiredness, frequent urination) could indicate pregnancy possibility. Look out for development of any other new symptoms if pregnancy is suspected. If periods do not start within 10 days of expected period dates, or if you get abnormal periods, or if you suspect chances of pregnancy, consider visiting your doctor/gynecologist at the earliest for thorough examination (to confirm pregnancy related changes/signs in body) and a repeat blood/serum HCG level test (to confirm/rule out pregnancy accurately). Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Take adequate rest. Drink plenty of water. Maintain healthy diet.
Take care.