Is the feeling of a blood clot in the leg a constant pain?

Maybe: This, again, is dependent on the location of the clot. Some people will have a cramping-type pain that worsens when there is pressure placed at the site of the clot. Some people may have intermittent pain at the site.

On the other hand ..: I agree with dr. Orringer. Usually patients with a DVT have pain, often it is constant. Typically it is made worse with putting weight on that leg. However, sometimes people with a DVT experience minimal or no pain whatsoever.