What Causes Pain In Heart Along With Shivering In A Child?

Good day doctors I have a son he is 10 years old every morning he told me that he has a heart pain and sometime his body shiver. I asked him if he feel the same when playing or running he said no I don t feel that pain but i feel tired, I don t know what should I do. Note: Before this symptom he was sick I took him to a doctor he was getting flu the doctor gave him amoclan 400 mg for 7 days and deline 0.5mg syrup for 10 days. Thanks in advence for helping me