What Is The Safe Period In A Month To Have Unprotected Sex?

Hi, me and my husband made love a day back i.e 2march, but we are not planning for a baby now, i have taken the pill at night only, also followed by the next capsule in the morning, and my periods still have a few days left usually at 13 of the month, so any chances for pregnancy as we did not use protection, Also do we have a time period in a month during which i can not conceive.