Hi. I Was Just Sitting Here. I Stood Up And

Hi. I was just sitting here. I stood up and my right calf instantly felt full and very tight and bigger than my left calf. I have very strong legs and calves are naturally defined. This was a very obvious and troublesome instant "filling up" of my calf feeling and physically appearing larger and tight and full.

Please advise as with the suddenness and strange part of it, not sure if I should get to a doctor?

Thank you! Michele