I Have Been Having Some Sporadic Mild Chest Discomfort The

I have been having some sporadic mild chest discomfort the last couple of days, usually with light activity. When this happens, I check my pulse with a sensor/app on my phone. The app says my heart rate gets up to 110 - 120, just casually strolling around the store. For most of my life I have had rather low blood pressure and heart rate. I am overweight and likely premenopausal. Any reason for me to be concerned?