As an otherwise healthy and fit adult male, my first symptom of my PE was a sharp stabbing pain in my chest when inhaling. Thinking I was having a heart attack, I self-admitted to the ER. I had 12 PEs in my lungs, and with ultrasound they found a 3" long deep vein thrombosis under my left knee. My left leg had absolutely no symptoms or pain. My PEs and DVT resolved with a 6-mo course of blood thinners, but I was lucky. PE mortality rate is around 15-20%.
Set your "stand up" timer for every 90 minutes and actually pay attention to it! And it wouldn't hurt to take a daily baby aspirin (probably should ask your doc first).