As you probably know, tetanus is a rare but very serious infection caused by a bacteria that lives in the soil and similar environments. Typically, exposure to rust or dirt, especially when it penetrates deep under the skin, is the scenario that sets up a possible tetanus infection.
To avoid this, nearly everyone is vaccinated against tetanus on a regular basis by their primary care doctor
. Therefore, the best approach would be to call your primary care doctor's office and explain to your doctor or to the nurse on call what just happened. They will be able to review your medical record and figure out when your last tetanus booster shot was (these are typically given every 5-10 years). If you are due for the shot, then they will probably recommend that you come in to the office to get the shot.
Most of the time, this can be done with just a nurse visit and will not require a lot of your time. However, if the injury
area is painful, looks red, or has any drainage from it, your doctor will probably also want to take a look to make sure it is not otherwise infected and requiring any immediate treatment.