Thanks for writing in.
It seems it is just a muscle pull. Since you are not suffering from shortness of breath
, there is nothing to worry. It can happen when there is some kind of stretch on that side or due to some minor electrolyte disturbances.
You can take calcium tablets 500mg once a day for 2-3 months, can apply some local ointment for relief of pain. Hot water fomentation might be helpful to you. Avoid doing any stretch that you think is causing the cramps.
Get well soon,