I took math level 2 sophomore year in june right after taking precalc/trig. Now I am rising senior and just finished ap calc ab. I really wanted an 800 on the test, and I plan on applying to competitive colleges like UC Berkeley. Should i retake in october?
Yes.
Yes.
By the way, Math II right after PreCalculus is a huge mistake many people do, IMO. If your PreCalc teacher is fantastic, then it’s fine. However, I recommend everyone to wait for after Calculus AB, and if you are fast enough, Calculus BC (end of 11th grade for me). You will actually cover vectors, polar, series, & sequences and those will just be easy points for you. Also, you will have more competency with your graphing calculator so it will be more of a tool for you.
Having taken Calculus, you can also “cheat” with some questions by actually taking limits, maximizing with derivatives, etc. Needless to say, the longer you spend doing math, the better you will get at it as well.
I would re take it. If you didn’t do that well in the class then maybe send it, but the whole point of sending in an SAT II is to show that you really excel in a certain topic and that you are specifically interested in a certain topic. A 720 is good, and it would be okay for certain schools but if you are thinking UC Berkeley then I would take it again and see where you land. Hope this helped! Good luck!! 
It’s very easy to get an 800, but you should definitely wait until you’ve had AT LEAST one semester of AP Calc. Use the Kaplan and Barron’s books to prepare.
@ccolumbus79329 I was able to retake it and got a 790. And I’m attending UC Berkeley this fall too . This post is so old, but here is my delayed thanks lol.