I Have Been Experiencing A Heaviness In My Chest That

I have been experiencing a heaviness in my chest that seems to be centered in the middle , along with gas .
I have also experienced a burning sensation that goes from my throat to my stomach.
I have just recently had a upper endoscopy where a disk was implanted , I had to wear a monitor which was used to monitor the acid level in my system. The results indicated that it was not acid. a Biopsy was also
done at that time , no cancer was found. Any idea as to what this could be ?