Strange tingling sensation on chest?

I don't really know how to explain what is happening. It only happens when I'm laying in bed trying to sleep. All of a sudden I get a strong tingling sensation or like a spasm in my chest. It feels like it's my heart but Im not sure I can't really tell. The feeling only lasts a second. It's not painful but it really scares me I think I'm having a heart attack everytime. It's becoming a problem because It's keeping me from sleeping. It doesnt happen every night but it happens very often. Does this sound like a certain medical condition or is this unheard of? I dont really know what to do. If you can help me thanks.