19 years old, heart disease?

So I have occasionally suffered from presyncope when standing up (that is, I stand up and suddenly feel very dizzy), and three times in my life have fainted, once after standing up, once while cleaning the windowless bathroom in hot weather and poorly ventilated conditions, and once when getting up late at night to go to the bathroom.  I have recently (1-2 weeks) had odd chest pains, sometimes on the left side but also sometimes on the right.  They aren't bad - an aching feeling at most, just once a stabbing pain on the right side - but they tend to last a couple of minutes, or longer.

I am 19, not overweight but not particularly active (I climb 9 flights of stairs once or twice every day, and go swimming or biking maybe once a week).  My mother has a heart murmur, my paternal grandmother had angina, and somebody else on my father's side has "heart disease".  I also have a history of stress, depression and hypochondria, as does my father, and my mother was clinically depressed, so I'm certainly not ruling out psychological causes.  I also moved two weeks ago, and carried a lot of heavy stuff; but I've read that if it was muscle problems, the muscles would be tender to the touch, and they aren't at all.

I am hoping to make an appointment with a doctor on Monday.  Can anybody share any advice?  Has anybody had this sort of experience?  Does anybody know what I could do, what I should watch out for, what might be wrong?

Thanks for your time

[kenkeith]

Your doctor will do a differential diagnosis for presyncope that include:

■Drop in blood pressure (orthostatic hypotension). A dramatic drop in your systolic blood pressure — the higher number in your blood pressure reading — may result in lightheadedness or a feeling of faintness. It can occur after sitting up or standing too quickly.
■Inadequate output of blood from the heart. Conditions such as partially blocked arteries (atherosclerosis), disease of the heart muscle (cardiomyopathy), abnormal heart rhythm (arrhythmia) or a decrease in blood volume may cause inadequate blood flow from your heart.
There can be a tilt table testing and that test may pinpoint the cause of fainting. It checks how changes in body position affects blood pressure.