Jorge,
I don┬┤t know where are you form, but from your name it seems you are from Latin america. Well I am from Uruguay, so maybe we are neighbours.
Regarding your GMAT, The retaking will depend on what schools are you targeting. If your aonly hope is to get into Harvard, Wharton or Stanford, maybe you should retake, but if your target does not "only" inlcude those schools, I think you a very good chance of being accepted.
About taking the exam more than once, I can tell you that schools will get information of the last 3 exams, but if you have already send the score, they will have the whole picture.
I have already taken the GMAT 3 times and I am going for the fourth later in August. My scores are lower than yours, but my target is only top ten schools, so I aim 680 or above. I think you have a good chance of being accepted at a top school, but you may find some difficulties in schools like H/S/W, Columbia, Kellog and Mit.
With your score you may well have a posibility in Chicago, UMBS, Duke, Tuck, and many others, even if you are lucky you can gain admission to one of the first group.
Hope this helps.
You got a 50 in Q, how was that you found difficult the math section. Your score is great.