I will try my best to answer your query.
I think it is palpitation
which is an abnormality of heartbeat
that causes a conscious awareness of its beating, whether it is too slow, too fast, irregular, or at its normal frequency.
Hope my answer will be helpful for you. Causes include panic disorders
, anemia, levocetirizine antihistamines, mitral valve prolapse, pyrexia , pregnancy etc. I think in your case it might be panic disorder or anemia, pyrexia.
I advice you to have an ECG done and i advice you to meet physician it is always better get yourself examined and rule out the causes.