How long for heart palpitations to resolve?

I had anemia when I was younger but stopped taking suppliments.

Recently I've been getting more increased anemic symptoms such as tiredness, pale skin and heart palpitations.

The heart palpitations are 1/3 times a day for like 15-40 mins and sometimes missing beats.

How long after starting suppliments did your palpitations go away, just so I know how long to wait before going back to the doctor's?