Yes, you can have a variety of different heart defects when you're a kid -- most of them congenital (i.e. you were born with them). If you are overweight/obese
, you could also have the beginnings of heart disease
However, what you're describing could be caused by a variety of things, and you REALLY need to talk to your parents and see a doctor as soon as possible. Your parents are tougher than you think they are -- don't risk your life just because you don't want to upset your mother. I can tell you, she'd MUCH rather worry than grieve.
Please don't wait any longer to see a professional about this.