Chest pains on my left side?

I'm 14 years old and I have been having problems with chest pains lately. I'm not overweight or underweight for my height and I have a healthy diet and a safe exercise routine for my age. They haven't been severe or anything but I occasionally get pains in the left side of my chest but it feels like the pain is inside more towards my back or it feels like it actually is on my back. And it also varies between sharp pains for a little time and then to a dull pain that lasts for maybe 5 minutes. I don't think that this will help any but I did get a concussion from soccer last month and I did land on my upper back before my head hit the ground so does that have to do anything with it? I don't want to say anything to my parents if it's not too serious so if I could get it clarified here it would be great.