Taking iron supplements for over a year due to anemia from periods. had ablation in december but still taking the supplements, cause iron overload?

Yes it is possible: Have your iron level (serum ferritin checked to see if you are still low, normal or too high.

It's a simple matter: To check one's fe studies to address issues of potential fe overload. You should see your pcp and express your concerns about your continued need for fe supplementation. I suspect, given your history, that they will want to check a CBC with red cell indices, serum fe, ferritin (best measure of fe stores) and TIBC (from which a %saturation can be calculated. Then can decide if fe is still needed.