Palpitations and high Heart rate.

I experienced palpitations and tiredness 3 days ago. I checked my BP and it was normal. I checked my pulse and it was elevated. I always have a high resting HR. Between 90-102. My GP said it's ok. But the HR was elevating when I stood up. Noticing this for 3 days. It rises up to 127-136 immediately after I stand up. It goes down if I stand in the same place or sit down immediately. If I start to walk, it keeps rising.  Also have palpitations while sitting walking and standing.  Went to my GP and he did EKG and he said it's ok and told me to see the hematologist. My hb is 10.9. iron 32.I have an alpha thalassemia trait.So he said that could be causing my symptoms and referred. I have not gotten any treatment for thalassemia.Diagnosed last year since I have low mch,mcv,mchc. Should I see the cardiologist to evaluate if it's any heart conditions.Since I have high HR and palpitations.Also feeling very tired throughout the day. Taking iron supplements everyday.  I am obese (103kgs).