I've been experiencing some random chest pain since I got over COVID back in May. It usually hits around the ribs or near my heart. I've had an ECG and echo, and even a stress echo, and everything came back fine. But now, with the colder weather, I feel this mild pain in my chest when I cough or do om pranayam, mainly in the heart area. My cardiologist thinks it's muscular, but I'm wondering if it could be something lung-related instead. Are there any tests I should consider to figure out if it's a lung issue or really just muscular?