The term “great aunt” refers to menstruation. It is possible to get pregnant if you have intercourse three days after your period, but the chances are small. Whether or not you will get pregnant after intercourse needs to be based on whether or not the woman is ovulating, if ovulation is irregular, then it is possible for a woman to ovulate three days after her period, so it is still possible to get pregnant if you have intercourse at this time, but the chances of this are relatively small. If a woman has a regular cycle, it is unlikely that she will ovulate three days after her period, and she will not get pregnant if she has intercourse in this case. If you do not intend to get pregnant, it is advisable to use contraception, and if you need to know about ovulation, it is recommended that you have a doctor’s guidance to measure ovulation.