Having sexual intercourse barely two days after the period ends has a huge pregnancy risk because the ovaries possibly produce eggs early in your cycle. One such example would be the morning-after pill with errors like the I-pill which should be taken within an hour of unprotected sex to lower the chances of fertilization else you can get pregnant. Nonetheless, it does not expose the rate of 100 percent. It is better to talk to a gynecologist to find out more information.