Thanks for this question Amanda
This could be related to many things
do you have a picture?
do you take any medicines? if so, which ones?
I am concerned you could have a blood clot in this leg
you need an ultrasound right away
especially if this was after a long trip
I don't think that would be related to a clot.
get an ultrasound ASAP
usually swelling and sometimes redness and pain
Not likely related
sorry about the late reply
was it checked for a clot?