SAT Subject Tests Help

I took 3 SAT Subject Tests in June, and I think I did poorly on everything but Math II (took lit, bio m, and math II). I registered for my scores to be sent to harvard, duke, etc. My question is should I cancel sending them until I figure out what my scores are and if i’m re-taking any of them?

Also, can someone tell me if these exams are even important? I’ve heard ambivalent answers and would just like to know. Because if i get average scores, I probably won’t even retake them. Yes, i’m applying to selective schools but if I have a good gpa, sat scores, and a nice essay - how much would this really matter?

not a lot as long as the rest of your apps are consistent