Need feedback on a possible 2nd DVT

[Nathan1822]

About 10 months ago I was diagnosed with a DVT in my arm. The belief was that an iv that I had received a month prior was the inciting incident for the clot. I remained on Coumadin for the entire time until recently. Until lately the only symptoms I had was occasional diffuse aching and stiffness. About a week ago I started to notice minor symptoms creep back into my arm that we're similar to the beginning of my DVT. Acute isolated pain in the inner elbow, the formation of a hard vein near the surface and overall, what I like to call, a numbing ache in my arm. Now the symptoms are similar, but in no way as severe as before. My question here really, is this. How can I differentiate the pain of Post Thrombotic Syndrome from another clot forming and should I take this seriously enough to console for another ultrasound?
I have also been diagnosed with factor 5 leiden if that is of any help.
Thank you for your time reading this and any feedback would be Paramount in soothing my nerves.