Hi Tinkerbell,
Welcome to the Pain Management Forum. I am sorry to hear about the pain that comes and goes.
If it were just your legs, or just your arms I would be more inclined to think it was a nerve entrapment, probably lovated in your spinal structure. However because it is both arms and legs it seems less likely that it is related to spinal issues.
If it continues to be bothersome or does not go away on it's own then I would consult your PCP. I wouldn't wait months. It's possible that you may have a generalized spine condition like DDD but at 21 that seems very unlikely.
Please let us know how you are doing. I will look forward to hearing from you again. I wish you the very best.
Peace,
~Tuck
Sounds like it could be from nerves. I get shooting pain in my leg but no numbness. IF it is from a nerve there are meds out there that can help so if it gets to the point you want to go to the dr make sure you tell him her what is going on so they can help.
Jamie