Need help with retake decision

<p>I just received a 740 on the chemistry subject test.
One can imagine the frustration one feels when he receives a substantially lower score than expected.
2010 May test was my second time taking the test after the 2009 June test, on which I got a 650.</p>

<p>The question is: should I retake to get a higher score?
I assume I have a decent (I’m trying not to trust myself too much these days)
chance of scoring 770+ this june.</p>

<p>However, I heard colleges frown upon students taking a subject test three times.</p>

<p>The thing is, I’m planning on majoring in chemistry in college.
I’m shooting for the ivies; Penn and Cornell are my top choices, and they both receive all test scores received.
I currently have an A in AP Chem and I’d like to assume that I got a 5.</p>

<p>so… should I?</p>