Hello,
Welcome to ehealthforum and thanks for writing
Unprotected sexual contact carries a risk of pregnancy but if after the act you had your periods which were normal in flow and duration then posibility of pregnancy does not arise.
This month periods can be delayed due to various reasons as stress,anxiety,hormonal imbalance,eating disorder etc.They might start soon in a week time.
Relax yourself and avoid any unprotected contact.
Take care!