Yes, blood clots can most certainly cause pain, especially if you have inflammation around the vein. I have had phlebitis (the inflammation part) and clots in my legs several times... always very painful. Given that you've had a clot in the past, you really need to have this checked out if you're still experiencing symptoms.
The first response I posted has not shown up, so will try again. Yes, depending on the severity of the blood clot and whether it is accompanied by inflamation surrounding the affected vein, it can be extremely painful. Given the fact that you've had a clot before, you really need to see your doctor if you are still experiencing any symptoms.