It isn't possible to come to a specific diagnosis with the history alone. These palpitations could be caused by :
- Strong emotional responses, such as stress, anxiety or panic attacks
- Depression
- Strenuous exercise
- Stimulants, including caffeine, nicotine, cocaine, amphetamines, and cold and cough medications that contain pseudoephedrine
- Fever
- Hormone changes associated with menstruation, pregnancy or menopause
- Too much or to little
thyroid hormone
I would advise you to get an ECG and undergo other investigations to find the underlying cause of the palpitations. If the problems persist or worsen visit the nearest ER at the earliest.