Last year I had a blood clot in left leg which happened while playing with my child. I underwent an emergency op, which was left a huge scar but was successful. I had no symptoms or pains previous to the accident. I fear I have a blood clot coming behind my right knee. But this time I have spasmatic pain behind the knee but that feels more like a ligament / muscular issue.
I take Warfarin 8mg (2x3mg and 1x2mg)

With your history you need to be examined by a Physician. No one here knows.