Never.

From 6th day to the 13th day of periods are considered as safe period. But I suggest you never venture into unprotected sex. Sperm have the capacity to survive inside the reproductive tract for about 5 days. You may indulge into sex during safe period but it is possible that your partner ovulates after few days. Sweetheart, ovulation is the synonym for “unprotected sex,” both of which can result in pregnancy.