Pulsing "heartbeat" sensation in my right leg

This has never happened to me before, so I am concerned. A day ago before sleeping I noticed the pulsing in my left leg and ignored it. I woke up the next day to it in my right leg. The pulse in the right leg is triggered by sitting or laying down and has lasted all day. I have been living a sedentary lifestyle recently due to college. I'm 19 and female. I am not overweight and my other living habits have not changed other than the part about college. I am not on any medication and I don't partake in anything such as drinking or smoking. I also have had less caffeine than usual recently. Is this something that will just go away? I tried to google the answer to this but I cannot find my exact issue. My legs are in no pain and look no different. I guess I just want to make sure I can ignore this safely. I would of course go to a hospital or something if I noticed swelling or pain because I think that indicates a blood clot.