Should I (and can I) drop the SAT II Chemistry Subject Test on test day?

I know this is extremely last minute, as I’m taking the Chemistry and US History Subject Tests tomorrow, but I’ve heard that you can make switches on the day off the exam(s) although there’s no guarantee. But I figured since I’m not switching to another test, just dropping one, they would let me, right?
Here’s the terrible story:
I’m taking AP Chem and APUSH this year. I’m doing pretty good in the latter, and not the former. I told myself that even though I had a terrible Chem I Honors teacher (as in, we didn’t learn VSEPR or what moles are, etc.) it would still be a good learning experience. Plus, I’m considering majoring in the sciences, particularly biochemistry, so why not? And previous students told me that even though some didn’t do well (well it was the first year it was taught at my school, so no one did well) college chemistry is now a breeze. These are pharmacy and chemistry majors as well.
I regret it completely now. I’ll be 100% honest, I was so not ready for the class and the challenge, especially with my schedule that was more packed than its ever been. By the time I graduate, I’ll have forgotten most of this stuff. Had a high C all year. I’ve been studying for the AP exam and am estimating a solid 3. I forced myself to sign up for this subject test because I know it’ll look very weird to not have a science and if I’m going to do a science ST it might as well be chemistry, right? Nope. Now I realize it would be better to hold it off, maybe do it on Bio, or take Chemistry in the fall when I’m not cramming for a million tests, and not basically prove to colleges what they already know about my chemistry skills.

Does this logic make more sense? I’m also cramming for the history test (since I was so busy trying to be more than mediocre in chemistry for two weeks now) and I’m doing so much better in it already. Estimating in the 700s. One night of cramming will probably give me a way better score than splitting my study time between it and chemistry.

Is this possible, and should I do it?

Just study for APUSH I guess. You are allowed to not take the test I believe. However, if you feel OK then take it. You won’t need to send in bad scores (to most colleges) and SAT chem is easier than AP chem I think.

From the College Board website: “Changes to SAT Subject Tests: On test day you can change which SAT Subject Tests you are taking, except for Language with Listening Tests. There is no charge for changing from one Subject Test to a different Subject Test. If you add a test, you will be billed for the additional fee. Note that some students may not be able to change tests on test day if required materials are not available.” Does this answer your question? https://sat.collegeboard.org/register/registration-changes

I was in the exact same boat as you (taking Chem and US History) and I decided not to take chem at the last minute. I don’t regret it AT ALL.