If i lay on my back and put my legs vertically in the air my pedal pulse becomes visible and i can feel it strongly in my right foot. the feeling and visible pulsing go away when i lower my legs. it doesn't happen in left foot. should i be concerned?

Since this maneuver isn't one that most physicians use during a physical examination, I'm not sure what the significance of your observation is. Because of gravity I wouldn't expect the dorsalis pedis or posterior tibial pulses would be more forceful with the legs vertically elevated. If conventional examination of these pulses , with legs horizontal or dependent, show normal pulsations no problem