pulsing

Ever since last night and I get this very fast pulsing that comes and goes  right underneath my breast more like the upper abdominal area. I read into it and many moms say they felt that but there are already four or  five months into their pregnancy and I'm only in my seventh week. I also read that it could be the blood flow. I just worry, has anybody gone through this and if so do you know what it may be?