Aortic Stenosis

I had a stress echo and regular echo within the last year. My peak pressure gradient was 14.9 mmHg and mean pressure gradient was 7.5 mmHg.  My AVA is 2.33 cm2.  My doctor told me that it would be a stretch to say that I have aortic stenosis. Does the pressure gradient indicate a problem?  Is it normal to have a pressure gradient under 15 mmHg?  I have no symptoms and performed well on a stress test.

[Cleveland Clinic]

You have mild aortic stenosis. A normal aortic valve normally does not generate any gradient at rest, and maybe only a small gradient with exercise. With this sized valve and your absence of symptoms you need no other treatment other than coronary artery disease prevention ( with a statin and maybe aspirin) and screening echocardiograms every 3-5 years.

[johnm82]

I have mild calcification of aortic valve as well.  I guess that is expected with the condition.  I am reading contradictory things.  Many sources indicate that aortic stenosis is the closing of the valve.  The pressure gradient is a way of determining how severe it is.  What else could be causing the pressure gradient?  The valve is the normal size.  I am 38 years old.  Does the early calcification mean that I am destined for severe heart problems or is it impossible to tell?