Fatigue is just another symptom to add to others like bloating, cramping, and tender breasts for many women. There are some indications that regular fatigue around the time of menstruation is associated with nutritional deficiencies, and particularly iron. If you're tired during menstruation, get checked for anemia and try to eat more healthy and iron rich foods. Drinking plenty of water to stay hydrated during "that time of the month" is another good idea, something that you can alternate with fresh vegetable and fruit juices, particularly the ones that comes from your own juicer. You can stuff anything in a juicer, including spinach and beets which are both great for your period.
At the same time, avoid caffeine. But, if you are not normally tired around the time of your period at all it might be one of the first signs you are expecting a baby. Fatigue and low energy is a notorious first trimester pregnancy symptom. For many pregnant women, including me during my two pregnancies, fatigue is a serious problem as well as one that very clearly shouts, Yes! You are Pregnant! It may well hit even before your period is due, but if that is the case for you, you will have to try and stay patient as you can't reliably take a pregnancy test before your period is due.