beta blockers/EKG and stuff

Well if you follow me on FB or Twitter you have seen I am on new medicine.I was born with a heart murmur and every now and then my heart gives me trouble.The last time was when I was pregnant with Stinky.I was put on Klexana until after she was born.Fast forward to now..about a month ago my heart started beating funny where I could feel it and see it.Beating very fast and it felt like it would "roll".I dont know how else to describe it.I went in for blood test because sometimes my anemia causes it to beat off key and the iron was low but taking extra iron did not help.I am having a lupus flare so I thought maybe that was it.Nope not getting better so I am on beta blockers now and will have a 24 hour EKG.I am scared,I know I cannot stop what happens and it happens for a reason but still scares me.