Thanks for posting your query.
You should not be pregnant because-
you had intercourse in safe period,
You had taken emergency pill within time.
Periods can be preponed or postponed due to emergecy pills.
So, don't worry & consult your gynaecologist to take progesterone
pills for withdrawal bleeding.
If you have any further query please let me know I would try to answer it for you.
Wish you a great health