My son had a little black speck stuck to the side of face. I scraped it off and it didn't look like a bug. Would I be able to tell if it was a tick?

A tick bite?? I doubt it very much that it was a tick, if it was attached to the skin you would have seen, now you scraped off it is more difficult to tell. Talk to your doctor. If you're worried about tick bite & Lyme disease your pediatrician can test him for it. Good luck.