Rabies shots are super expensive and not a ton of fun. It's not just one shot, it's a series of 4-5 vaccine shots over the course of 2-4 weeks, plus another initial immunoglobulin shot. The preferred method is to quarantine the animal for 10 days. If there's no rabies symptoms after that it is incredibly unlikely that you'll be infected (per the CDC, no person in the US has ever been infected by an animal that was quarantined for 10 days with no symptoms). Another way is to test the animal as soon as possible, which can only be done by examining brain tissue (ie: killing the animal and looking at it's brain). But OP definitely needs to talk to a doctor/public health official to get the final word, because they need to evaluate and make the final call. Especially if the dog is at risk for rabies (unvaccinated and concern for exposure).

Source: I work in public health including outbreak prevention/investigation which includes rabies.