Hello! After a careful review of your discussion, I would like to suggest you
1) Considering your age the symptoms of feeling of abdominal pulsations is generally an absolutely normal phenomenon due to thin abdominal wall. So, you need not worry at all!
2) Sometimes the abdominal pulsations may be due to an abdominal aortic aneurysm
, so it would be better to have consultation with a cardiologist & investigated further.
Thanks & take care of yourselves!