I developed an arm clot, on the port side. Was then tested, and diagnosed with Factor V, and treated for 5 years with warfarin (anticoagulant). Now on baby aspirin, 3x/week.
You might ask for testing for this common blood clotting disorder, as it may help determine your best treatment course. It's genetic, so all my sibs were tested too.
Good luck, 11 year survivor!
Kathy