If you had already stopped using the pills before you had sex, the chance of pregnancy increases. Having sex at the end of you period may result in pregnancy if you happen to ovulate earlier than the norm... which some women naturally do. Odds are in your favor that you would not become pregnant from sex on the fifth day of your period.
If you were still using the pills when you had sex, but stopped taking them shortly after, you are still protected (although no method of birth control will be 100% effective).
You will have to wait until you are due for the next period and see what happens.
|