You will not be penalized for taking the LSAT more than 3 times. Although in my experience speaking to administrators of the LSAT, writing the test twice, is usually a good indicator of the best score you will achieve. If you are seeing that your score is getting higher each time, then use your best judgement. Law schools will always take your best score, but keep in mind that they will take a look at your previous attempts as well. Good luck!