Will a 34 get you certain scholarships? A 33 is very high. What happens if your score goes down the 3rd time? Will that hurt you in the admissions process? Some schools require that you submit all of your test scores. On the other hand, some schools super score.
How much time will you spend prepping? Could you use that time to do something impressive in your extracurricular activities, or get more involved in your community?
If you don’t have a specific study plan to target your weaknesses another test is unlikely to give spectacular results. 33 is a very good score. Schools don’t just look at the score, although it helps. I don’t know anything about your schooling or extracurriculars, but it’s likely that the effort that you’d spend to get one more point would be better spent on making you a more interesting candidate for your potential field of study.