Our biggest worry when taking an exam is failing. It's totally natural to want to know your options. However, if you are taking the FE exam, that should be the least of your worries. Thankfully, you can take the FE exam many times. If you fail, you can apply and retake it. The NCEES generally allows candidates to take the exam three times a year, during a two-month window. Nevertheless, some licensing states' boards may have different policies, which is why you have to check with your State Licensing Board before you apply for the exam. Overall, examinees have several attempts to pass the FE exam. However, studying for an exam over and over again is exhausting and honestly a bore, which is why you should prepare well and strategically to pass it from the first attempt.
Retaking the FE exam, is in fact, very common among examinees in all disciplines. And even though failing the exam is not the end of the world, you should do your best to avoid it in order to move one with your career and become the engineer you have always wished to be.
If you fail the exam, don't try to retake right away. Enjoy life and take the time to focus on your pitfalls and the reasons why you failed. You can use the diagnostic report sent to you by NCEES that will help you identify the knowledge areas in which you need to improve.
It would be best if you also took some practice exams, not only for practice but to find the issues you have. Figure out the solutions to the problems you couldn't solve and start from there to cover bigger issues areas. Sometimes, the problem is not the lack of knowledge but rather the lack of the right test-taking strategies and habits. Take the time to rethink your habits during exams and how to improve them to pass the FE exam in your next attempt. You should also know that if you fail the exam, you have to apply again. This means that you have to pay the fees of $175 to retake the exam.