I have heart palpitations ? I have no chest pain though. What should I do?

The palpitations occur on the left side of my chest. It rarely occurs on the right side of my chest. I noticed when im stressed , I get irregular heart beats . Sometimes I experience fluttering in my chest. This has occurred off and on for the last few years. I think it might be related to anxiety. Sometimes i think i have anxiety attack. I notice sometimes when im on train and its crowded, my heart starts beating fast. I feel this is anxiety. I also might have social anxiety. Im a friendly and outgoing guy though. Anyway should i go to a therapist or seek some other kind of treatment whether it be mental or physical. My palpitations don't occur all the time, only when im stressed. I believe it's due to my mental health.