You may be experiencing PVC'c Premature Ventricular beats or Flutter.
If you feel it for a long period of time you can go to the nearest fire station and ask to be monitored that way it documented. See you primary care
doctor so you can be referred to a Cardiologist. They have 24 hour holter monitors that can be placed on you or 30 day event monitors that you can place on your chest and scan when you feel your symptoms occur....Make an appointment soon to talk to your doctor. I work in a cardiology office, don't brush it off as gas. Good luck.