I saw the doctor just a week ago because my right leg has been hurting, too. The doctor said that with blood clots, there will be swelling in the leg vein and most of the time the leg will feel hot to the touch. Also she said it would most likely be hurting when I walked on it and the pain would be in one area of the leg. This is not a difinitive test, but sometimes if you straighten your leg and flex your heel and you feel a sharp pain you can tell if one is there. But it doesn't always work. She also said it will get worse, not better if you have one.
She said that my pain could be from a number of things; a calcium or potassium deficiency, regular vitamin deficiency, dehydration, or stress or anxiety. In my case she believed it was all of those things.
To prevent them she told me to make sure to keep your body moving, even if you're sitting down and watching t.V. Still move your legs if you can. Also don't cross your legs. Also take a multivitamin every day, and drink lots of water cuz it keeps your blood from thickening. I also take a low dose aspirin(ecotrin) every day.
If you're under a lot of stress or have anxiety that could be causing it. Anxiety can cause tons of different pains and I think i've had them all at one point or another:).
If you really think it is one though, I would get checked since you do have some risk factors. If you end up being okay, try to do those things that prevent them, it will put your mind at ease in the future.