I have a stethoscope and whenever I listen to my heart, it makes the normal "lub dub" sound, however, when I place it on the upper part if my chest, I hear something like a "ta lub dub." I have health anxiety and always worried about this. I've had an EKG and a holter monitor back in January of this year, all normal. Should I be worried? I feel fine otherwise. I'm 25 years old, female, do not smoke, no drinking, and I am fairly active. Thx.