Oh, by all means send him straight to the clinic for a health check! You must be a responsible hidden alien parent.
What's the worst that can happen? I mean, what are the odds that his regular doctor will be out that day and Vasilios will be examined by a strange quack doctor who will be overcome with Evil Scientist Vibes and want to kidnap him for examination/cloning/dissection or other Evil Scientist things, possibly in conjunction with the Men In Black and/or the Military.
Nah, that could never happen, right? >:)