Seconding the suggestion to have your iron levels tested and if indicated begin supplementing with it. The first most likely cause of anemia is menstruation. The second most likely cause is gastrointestinal bleeding. It sounds like you've got both situations.

Eating more red meat, especially organ meats like liver will also help bring your levels up. These dietary sources of iron contain heme-iron which is readily absorbed by your body. All vegetarian sources of iron as well as iron supplements contain non-heme iron which is absorbed but not as easily. It's important to get tested before taking any heavy-duty iron pills because it is possible to have an overload of iron.

Also make sure you're getting enough B12 and vitamin C, those are important cofactors to utilizing iron.