It is possible to get pregnant if you do it on the last day of the fertile period. The fertile period is also known as the ovulation period, and even if it is the last day, there is a possibility of pregnancy as long as the woman has intercourse during the fertile period without taking safety measures and the male penis ejaculates in the woman’s vagina. If you do not plan to have children for the time being, it is important to use birth control during the fertile period. If you have unprotected sex, you may choose to take oral emergency contraceptive pills within 72 hours of intercourse, the sooner you take them the better.