Yes, a ferritin level of 7 is low and you are recommended to consult a doctor to know the right ways to treat iron deficiencies.
You can increase your ferritin levels without affecting your iron by consuming more copper-rich foods, like shellfish, liver meat, fatty fish, oysters, spirulina, mushrooms, shrimps, and dark chocolate.
A ferritin level blood test helps your doctor understand how much iron your body stores. If a ferritin test reveals that your blood ferritin level is lower than normal, it indicates your body's iron stores are low and you have iron deficiency.
The normal range for ferritin in your blood serum is 24 to 336 ng/mL for adult males. For adult females. Hence if you have a value of 33 then it falls within the range.
Low ferritin levels are anything ranging for men <40 ng/mL. For women: <12 ng/mL.