You are ready, don't postpone! Unless you have a target score of more than 250 than that is different. You've been studying for months, it's time to take the exam because you have reached your "peak." If you keep postponing your scores will start dropping, this happens to many people. Just remember that everyone has their "peak" and that is fine. Good luck, I also told myself I will not take the exam until I get over 220 on the NBME. So far I took Nbme 12 and nbme 13 and i'm at a 209, so I still need more than a month at least. Be confident.