Is it normal that my calves ache when walking or exercising now that I've had a triple bypass?

No. Aeteriosclerosis is a systemic disease.Peripherovascular disease is the same process of plaque formation creating significant flow reduction distal to the stenosis usually involving the arteries to the legs. Calf claudication may pccur from critical stenoses on the superficial femoral, above knee popliteal, femoral or iliac arteries. Need ankle/brachial study, possible contrast study.
No. Your bypass was performed for disease in the heart arteries ( atherosclerosis ). Remember, atherosclerosis affects all arteries, some more than others depending on the rate of progression of narrowing. Your leg symptoms ( claudication ) most likely are due to atherosclerotic narrowing of leg arteries or the pelvic arteries leading to the legs. Accurate diagnosis is needed to determine treatment.