What are the chances of me ping the AP Calculus test and the AP US history exam?

You can p both, as long as you prepare and keep yourself on track. Alot of people stress out about it but I'll let you in on a secret, the exams aren't that hard as long as you study. Stop stressing over it because it will only hurt you in the long run. You need to have a positive attitude about it: "When may comes, I'll be ready and prepared to take and do well on the exam."