Grrrr! I just typed up a message and it must have gotten completely erased. Anyway, you are feeling your own heartbeat. It will begin getting stronger and stronger because eventually you will be pumping 40% more blood through your body than usual.
The baby's heartbeat is MUCH faster (130-180 beats per minutes) and it takes a doppler to pick it up. Before too long you will get to hear it at every visit. It's so awesome to hear it!