Pass/No Pass is calculated as a C - at least it was 3 years ago when MSIII was applying for medical school in CA. I'm assuming its the same for pharmacy. It may have all changed now though.
She was actually given the heads up about this in high school when her cousin applied for a masters engineering program a few years before her. She asked about it at her UCSD pre-freshman visit & it was confirmed by one of their admissions counselors. She did her undergrad at UCSD & by not taking her AP tests, she was able to start her "series" classes at the first level. That meant she was able to do very, very well. If you get a 3 or 4, you start with the second quarter class. G*d forbid if you get a 5 - you must start with the third quarter class. It won't matter what high school you take calculus at - the collegiate level is much, much harder & its easier to start at the beginning & do well than struggle to get up to speed with how the course is taught at the campus you attend. You are also competing with the very cream of the crop & for the most part, they grade on a bell curve. Someone is on the downslope of the bell. Also, for an incoming freshman, it becomes an "easier" A which gives you time to become adjusted to a collegiate setting rather than a high school setting which gives you a better start.
Be careful in CA with the AP credits!!! They have become meaningless in CA & the UC's know it. Take the exam in classes which won't be your major. If you want to go into a science oriented professional school, start with the first class of your series (for pharmacy it should be the higher level math & chemistry offered) & get A's. Those look soooo much better than high school APs which are inflated.
If you are in high school, visit a professional school campus - it won't matter which type or one. Ask specifically how they calculate a pass/no pass grade when calculating the gpa. All professional UC schools should be the same - medicine, pharmacy, law, etc.. That won't necessarily be the same for the private schools - they may use different criteria & I'm not familiar with those.
Its important to realize you won't get this same advice in your high school. The reason is - the high school gets $$ for each child who is qualified who is enrolled in the class. Then, the school AND the instructor get $$ for each child who passes the test with increasing amounts depending on the score. Its worth it to the school, for many reasons - not just money, to have you take the class & pass the test. It may not be worth it to you in the long run however.
Be careful & good luck!