I've had a 2D echo and an ECG, and both came back normal, and my TMT was negative too. But sometimes I get this pinching pain on the left side of my chest that lasts for about 9-10 seconds. It really freaks me out and makes me anxious, thinking there might be something wrong with my heart. What could this be and what should I do about it?

It's good that your 2D echo, ECG, and TMT results were normal. The pain you are experiencing could be due to anxiety or muscle strain. To alleviate the pain and anxiety, you can take Tab. Paracetamol 500mg as needed for pain relief. Additionally, practicing relaxation techniques such as deep breathing exercises or yoga can help reduce anxiety. If the pain persists or worsens, it's advisable to follow up with your healthcare provider for further evaluation.