1) I have never heard of that and i wouldn't be happy top leave it at that.
A DVT is unlikely but must first of all be excluded and if it were my leg i would ask if i could have a venogram which is dye inserted into the lower leg at the ankle and the scanned.
If that was normal, as i am sure that it will be, then we can move on.
2) If this is one leg only........be absolutely certain that the opposite leg is also not swollen, but unnoticed because of your swollen left leg.
If they are both swollen, then we may need to look for a systemic cause....heart problems.
If this is indeed just one leg, then that is very unusual, particularly if the venogram is normal and i am afraid that at this stage, i am stumped.