The only common side-effect of warfarin is hemorrhage (bleeding). The risk of severe bleeding is small but definite and any benefit needs to outweigh this risk when warfarin is considered as a therapeutic measure. Risk of bleeding is augmented if the INR is out of range (due to accidental or deliberate overdose or due to interactions), and may cause hemoptysis (coughing up blood), excessive bruising, bleeding from nose or gums, or blood in urine or stool.
also another sidaffect is:
Warfarin necrosis, This rare reaction occurs usually between the third and tenth days of therapy with warfarin derivatives
Another rare complication that may occur early during warfarin treatment (usually within 3 to 8 weeks) is purple toe syndrome. This condition is thought to result from small deposits of cholesterol breaking loose and flowing into the blood vessels in the skin of the feet, which causes a blueish purple color and may be painful
so i dont think it could be the warfarin i would get a second opinion though just to be on the safeside xx