History of dvt w/vinecava filter tightness above knee w/swelling in calf and ankle itching behind the knee and aching on lovenox (enoxaparin) 120 sub q2x day new clot?

Possible: Unfortunately, though rare, you can still develop a clot even on medication. The filter doesn't prevent clot it just prevents it from shooting up to the lung.

New clot is possible: Although you are anticoagulated with lovenox, (enoxaparin) it is still possible to have a another clot. The fact that you have a ivc filter should protect you from developing a pulmonary embolism. You may need to switch your anticoagulation agent to another low molecular weight Heparin or xarelto or warfarin.

Ultrasound: On Lovenox (enoxaparin) it would be unlikely to develop another blood clot, however if you have a hypercooagulable condition there is some risk for excess clotting. Have an evaluation with your doctor and you may need an ultrasound to look for progression of the clot.

Likely: The vena cava filter will nöt prevent clot DVT but will decrease embolism to the lungs. The Lovenox (enoxaparin) should reduce your risk DVT . Based on your history it appears you have a hypercoagulable condition. This may be due to some factor like apac, c, s deficiency or malignancy. See a doctor as thrombophlbitis should be considered.