Concerned a little

So I have always had some type of heart palpitations for over my lifetime I am 25 and when I was 20 I got hit by a car and the doctors put medicine in my IV and said it was to reset my heart ! Well I have had two kids since that day 5 years ago and it seems as if since I had my second son they have become more and more there ! When I was in the labor and delivery room after my epidural my heart started raising it went down and they had no concern for it but it seems lately it has been worse . Any one else have this and give me some peace of mind that I am not gonna die ! I should mention I had a baby 5 months ago