How can I find out how much plaque is in my arteries, and how can I get rid of it?

Many of the men in my family have had heart attacks, and have died from them. I am two months from twenty eight, and I imagine that now is the time to nip this problem in the bud. I know exercising can keep your heart strong and healthy, and that eating foods that are low in bad fats will help. Is there a way to keep track of build up, or do I just have to be good all the time and hope it is working.

I ask this with an open heart.