i've decided against taking USH

<p>last october i took math IIC and received an 800
ad i was planning on taking ush and physics tomorrow, but after continuously receiving horrid scores in history (610 - 640 range), i've decided that i wont be taking it.
this means that i will only have two subject tests (math2, phys) although im confident i can pull an 800 in physics
should i take literature in november to add another test to my application??
i need advice
is it worth it to take that additional test and how much would it help me if i did?</p>