What people think are period during pregnancy are not periods, so in answer to the question “can a girl get pregnant during her periods; there is no way a pregnant woman can have periods. She may shed blood but this is what is referred to as implantation bleeding that happens right after implantation when your period may have been due. The explanation behind periods is plain simple, it happens when the body prepares to host a baby every month but when it is not able to do that, the lining of the uterus is shed. However when you have unprotected sex and your body starts producing the human chronionic gonadotrophin hormone for the support of the pregnancy, you will not have periods for the next nine months. What you may think are periods will happen in the first weeks of the pregnancy but this will not go on for longer than you expect and will not endanger your baby. Still though, you need to pay attention to any other bleeding that may take place that may pose danger to the fetus growing inside you. if the bleeding is too much and is accompanied by a lot of cramping, you need to seek specialized help from your gynecologist.