What does the spot after a tick bite look like?

Erythema Migrans. The rash may not be noticed at first, but will usually starts as a small spot that expands as a reddish-pink ring that can get quite large. This is associated with lyme disease, and if you think you may have this rash, even if you don't remember a tick bite, see your physician immediately.
Often a red spot. The primary infection of lyme disease is a rapidly expanding ring. This should be promptly treated. A temporary red spot is a reaction to the tick rather than lyme.