I have had all my tests 3 yrs ago but they keep finding my iron levels low and they keep putting me back on iron. worried is this normal .

Fe deficiency.: By "all my tests" i assume you mean you had a thorough evaluation for blood loss including upper and lower GI examinations. If iron levels remain low despite negative exams you must be losing iron in menstruation or failing to absorb iron. The treatment would be to control menstrual losses and to supplement your iron. Your doc should have a better understanding of which problem you have.