<p>So i just registered for SAT 2 chemistry...but im thinking i might want to add APUSH and retake AP BIO, would this be wise to do when i get to the testing room, or possible at all? Or do i have to register before april 3rd for everything?</p>
<p>i meant not AP but those sat subject tests</p>
<p>Probably you want to register now. I think on testing day you can pick whichever SATII's, but don't know if you can change the number of tests you signed up for.</p>
<p>You can add the US History & Biology subject tests on the testing day (the fees will be charged on your bill) if you can't make up your mind by April 3rd. There's always the late registration deadline, too.</p>