A flutter in my chest

im an 18yr old female with a fluttering sensation in my chest on the left side close to the center of my chest.
Im very sure its my heart.
i was born with a heart murmur it was taken care of, and at my last visit to the doctor it was said that i had one. this last visit was the first time a heart murmur had been mentioned sence my youth. the doctor called it benign.
this was back in july.
I have had flutters a good part of my life. but only when i was under high stress or when i was having a panic attack. these flutters only happend once and for only a secound. they never occured more than once or twice in a day.
today however the flutter has occured periodicly all day long.
im worried. is this serious? and does it have anything to do with my heart murmur?

[deedle1976]

You are probably having PVCs, which most people have every day but don't feel. . People who can feel them usually describe them as a skipping sensation or a fluttering in the chest or throat. I  used to have that horrible flutter more than once a minute every minute, every day. A 24 hour holter monitor showed they were  PVCs. You could ask your doctor for a holte monitor to confirm what's causing the fluttering.  Your doctor can decide whether you need an ultrasound to have a look at your heart (echocardiogram). These tests almost always come back normal though.