Perplexed by my 550

I took the GMAT two weeks ago after three months of intense study. I used Kaplan, Kaplan 800, OG11, and GMATPrep as my prep materials. I scored in the high 500s on the Kaplan test (seems to be a normal thing) and scored 710 and 690 on the two GMATPrep tests. My quant score was 43rd percentile and ve...