Thanks for your question on Healthcare Magic.
I can understand your concern.
Yawning and Fluttering sensations in chest are commonly seen with
arrhythmia (rhythm disturbances in heart).
So
consult doctor and get done ecg, 2d echo and Holter monitoring (24 hours continuous recording of ecg).
If all these are normal then no need to worry for arrhythmia or other heart diseases.
Sometimes, uncontrolled stress and
anxiety can also cause similar symptoms.
So
consult psychiatrist and get done
counselling sessions. Try to identify stressor in your life and start working on it's solution.
You may need anxiolytic drugs too.
Don't worry, you will be alright.
Avoid stress and tension, be relax and calm.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.