Hi,
Thanks for the query.
If you had
unprotected intercourse around the time of ovulation, there is possibility of
pregnancy.
Sometimes urine pregnancy test kit may not detect early pregnancy.
So you wait for one more week, possibly by that time you will get periods.
If not consult gynecologist, get examined and go for
ultrasound.
This will find out the possibility of pregnancy, in case of absence of pregnancy, the cause for delay in periods can be made out.
And you can take tablets for withdrawal bleeding with your doctor's advice.
Take care.