I Had Foot Surgery On July 13 And After 6

I had foot surgery on July 13 and after 6 weeks I was checked for blood clots. I was told I did have one and I was put on Warfrin. I am now having strong lower back pain, especially in the morning when I get up. After a few hours it lessons but is still uncomfortable. I have a doctors appointment next Wednesday but I was not sure if I should try to get in sooner. I mainly want to know if Warfrin causes back pain.