If you did your best to write a complete, clear, and insightful essay within the time allotted, you should have nothing to worry about.
Understand your assignment: What is the goal of this essay? What is the length and deadline of the assignment? Is there anything you need to clarify with your teacher or professor?
Unless if you finished way ahead of schedule, don`t worry about major revisions like reorganizing the structure of the essay–it`s better to hand in an essay with an imperfect structure than a paper that`s impossible to follow because you had to stop halfway through the revision process.
Without a clear plan, you run the risk of realizing partway through that you`ve drifted off topic or written yourself into a corner, and fixing these mistakes will consume a ton of extra time.
On the topic of planning, it`s important to sketch out an idea of how long you want to spend on each section of your essay. If you know the number of paragraphs you`ll need to write ahead of time, you can do this before the exam even starts!
You should formulate your thesis statement—the central argument you`re going to make. The thesis statement provides focus and signals your position on the topic. It is usually one or two sentences long.