On my period, anemic, feel dizzy forgot to take pill for anemia. normal?

Long-term issue: Anemia due to menstrual bleeding is usually a chronic process. The treatment is long term. If you are taking supplemental iron, you should take it daily (every-other-day if constipation is a problem). Missing one pill should not make a difference. Make sure you are well hydrated. If the dizziness continues see you physician as soon as possible.