I have been having chest pains for the past 6 years or so.  It started out as a sharp pain that I could control by stopping breathing for a minute.  It became so regular that I stopped breathing without thinking about it.  There would be times I would get the pains while sleeping and would just stop breathing while sleeping to get the pain to go away.  Over the years, the pain progressed.  It would radiate throughout the back, ribs, and full chest.  The pains would not always be on a certain side of the body.  I can no longer stop the pains.  The pains have gotten so bad that they paralyze me anywhere from a few seconds to 20 minutes (the pain is so bad that I cant move).  Recently, I have noticed that if I lay down on my left side, I immediately get a pain in my upper left chest as if it were in the heart.  I am 21 years old and do not smoke.
Thanks for your question on Chat Doctor. I can understand your concern. Possibility of stress and anxiety related chest pain is more likely. But better to first rule out heart diseases because you are having left sided chest pain. So get done ECG and 2d echo. If both these are normal then no need to worry about heart diseases. Better to consult psychiatrist and get done counselling sessions. Try to identify stressor in your life and start working on its solution. You may need anxiolytic Chat Doctor.  Don't worry, you will be alright with all these. Avoid stress and tension, be relaxed and calm. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.