It is certainly normal for you to have pain on the fifth day of the menstrual period. As your period last for five days it is usual for women to have pain during any of those days. It is on the last day that a lot of women suffer menstrual pains. So there is completely nothing for you to be scared of. Your pains will pass after you get older. The menstrual period is a very tough time that keeps on occurring in every woman's life as she develops. It is always good to share such issues with other women, if you feel you have a problem.