Okay this seems very low to me. I was shopping and stopped off to check my blood pressure, as I always do at this same store every time (used to have really low bp, so I check it frequently. It's been fine the last few years). My heartrate is usually high 70s, but last night, while pushing a very heavy cart with sleeping baby, etc, it was only 56. I've heard of like 50 happening to some people while meditating, but I was pretty active at the time. Should I worry?