I am warried because I recently changed my AP Physics to regular physics. I changed the class because I got very low grade so I decided to just change it. And now I’m warried since I am a Junior in high School will it effect my choices of university and my career. By the way I have AP Biology, AP US history and AP Psychology those are all my ap classes.
Overall, it’s usually better to get a high grade in a “regular” class than it is to get a very low grade in an AP class. If you’re planning on going into engineering, it might look a little odd, but that’s about it. Now you just have to get good grades in your new physics class - if you get the same grades you were getting in your AP class, that’s where it would make an impact on your college admissions prospects.
Thanks
There is no honors Physics?
What major are you thinking about?
If you have taken Bio, Chem, Physics, then next year you can take an AP class.
You’re better off with a good grade in regular physics than with a C or lower in AP physics.
As long as you have biology, chemistry, physics, and an AP science (AP bio, AP chemistry, or APES) it won’t hurt you.
Btw you should have 4 years of English and social science/history, Foreign language through level 4 (3 for less selective 4-year universities), and math through Precalculus or calculus.
Thanks for the advice
Is it ok to do calculus in my senior year
Yes. Calculus senior year is best, especially for a future STEM major.
cf. #4 
Sounds like you did the right thing.