I Feel Heart Beat High And I Feel Tired As

i feel heart beat high and i feel tired as we feel very weak at late night. i feel something is producing under my stomach. i touch my heart i feel heart beat sound like rapid songs.. it unusual because i check my heart normally.
it happens simply.. for me. sometimes stressful.. sometimes unusually like i not stressed nor working.
last weak before i had that feel same time i was with doctor . he kept some finger clip it shows 115.
what it would be now? than that.!like now i feel...
i am asking is it ubnormal condition now.. i have meet a doctor?