Thanks for the query.
You didn't mention how you verified the ovulation.
Usually after ovulation it will take around 14 days for the onset of periods.
But according to your previous cycles 27 days cycles, you should have early ovulation.
So you better consult gynecologist, undergo follicular study
to track the ovulation and plan unprotected intercourse
around the period of ovulation. This can increase the possibility of pregnancy
Don't use pills for postponement, that is not correct.