I Often Get Pains In My Right Leg, Sometimes In

I often get pains in my right leg, sometimes in the thigh, at times the knee and now my foot. I have a clotting disorder and take Warfarin. The pain usually last a week or so and come and go without having had any injuries. Since my foot started to hurt I learned that if I take a deep breath and exhale, as I exhale my foot gives one large painful throb. Could it be related to a circulation issue or a blood clot? I have had an IVC filter in for more than six years and no doctor is willing to remove it although they say it should come out due to possible future fracturing or dislocation. I also get on again / off again left arm pain. Thank you.