can alter the menstrual cycle depending on the period of menstrual cycle when you took that.
As you took the pill at the time of starting of menstruation
means at the second half of previous cycle, because of high dosage of hormone in the pill your periods stopped.
And also because of pill your periods might have got postponed.
As you had intercourse around the time of menstruation, in case of regular periods ovulation is very rare at that time so also chance of pregnancy