Get very weak when i have period first 2 days heavy! pain above stomach?

Check for anemia: Blood loss from menstrual periods can be result in anemia in some women, especially with heavy periods and/or diet is not high in iron. If hemoglobin is already running a little low due it may drop enough to cause weakness when a woman experienced heavy menstrual bleeding. A simple blood test for hemoglobin can determine if you are anemic. You may need to take iron. Also, drink lots of water.