Is something wrong with my heart?

Every once in a while my heart will speed up so fast like it's going to pop out of my chest & it won't slow down until I inhale as deeply as possible and exhale as much as I can. It will go on for five minutes if I don't do the deep-breathing. This will happen when I'm just sitting down relaxing & not doing anything at all. It happens maybe just like three times a month but I still want to know if it's normal. And I don't have health insurance so telling me to see a Dr. about it does no good. Does anybody else experience this? I'd appreciate any help. Thanks.