Thanks for the query.
If you had unprotected intercourse
around the time of ovulation, better to rule out the possibility of pregnancy once before going to withdrawal bleeding.
As sometimes urine pregnancy test kits can give false negatives, you once consult gynecologist and go for blood test
for pregnancy or ultrasound
After ruling out the pregnancy you can take duphaston
with your doctor's advice.
By doing ultrasound the possibility of recurrence of PCOS can also be examined.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429