Haeviness and minor pain in chest area.

Since past 3 months I can feel heaviness and minor pain on both sides of chest but pain goes automatically it's not consistent but heaviness is still there but I can do my regular activities without any issues. I can run ,take stairs, breathing exercises and also I am tracking my daily walks. Everyday I walk for almost 1 hr without any issues. 2 months ago I consulted cardiologist and he asked me to go for stress test, lipid test and few more blood test and all my reports were normal and he said it is not related to your heart and asked me to join the gym but heaviness in my chest still present even after 3 months of consultation from cardiologist. While coughing I can feel that heaviness but it is not consistent whole day as well. Can someone please suggest me the treatment for my weak chest and how I can get rid of this heaviness on my chest.