I am worried that it might be something bad. It is white and oval or egg-shaped and has blue arrows on each side. Can anyone help?

Why don't you just ask your teen? Open communication is a good thing.

As to identifying the pill... I would take it to a pharmacist and ask them to identify it for you. If you would feel better doing this before speaking to your teen, that would at least give you the knowledge of what kind of pill it is so you can tell if the explanation fits.

Good luck!

Didi