Hello.... the symptoms described point to a muscular strain, a very common problem faced after a "unaccustomed" strain/exercise.
The popping noise you feel in the left shoulder needs to be reviewed, as it points to a instability of the joint, and perhaps a recurrent dislocation, with spontaneous restoration. This surely could be the cause of your pain, but this pain is usually around the shoulder only.
You need to continue with the exercises BUT at a slow / reduced pace. Use hot water fomentation / gentle massage
with a diclofenac
cream and a analgesic
1000 mgm on a as required basis, NOT more than 3 atleast 6 hours apart.
Remember cardiac pain is a sharp intense pain, with sweating, breathing difficulty and vomiting