Palpitation. 22/8/18 hb is 16. 2g/dl!

I have palpitations since 2 months and doctor suggested to ecg ..the ecg is normal they said it is ANXITY nd they precribed some tab pan 40 anxit.5mg for 10 ..after 10 i vesited again they palpitation is not cured ..they suggest 1more ecg the ecg are normal again they suggeat to do chest Xray  are also normal ...and Blood pressure also normal  they priscribe pan 40  parasip 500 and anxit .25mg tab... After using althose medicine the doctorsaid ...they not saying anything its normal..butbi have palpitations ..i dont have any anxity dippression and other tention..i dont no why it is happining... What is its cause please help me Please suggest me any medication/advice what i have to do why it is happining... My hemoglobin levels Dated 5/8/18 is 17.0g/dL.  Dated 22/8/18 hb is 16.2g/dL