Having unprotected sex during your period does carry a lower risk of pregnancy, but it is still possible. It is important to keep track of your cycle and be aware of the fertile window in which pregnancy is more likely to occur. If you are concerned about pregnancy after having unprotected sex, you may consider taking emergency contraception. In any case, if you experience a significant delay in your menstrual cycle, it is recommended to take a pregnancy test. It is always best to stay informed and take necessary precautions to avoid unwanted pregnancies.