Plan B

Hey everyone I’m 16 years old and had a condom slip while having sex with my boyfriend. The condom was inserted all the way inside me and was completely off his dick. Gladly he didn’t cum inside me, but we rushed to the nearest Walgreens and I bawled in the car for 20 minutes. After I took the pill Ive been experiencing every single symptom on the box. And tomorrow is my first day of senior year, I’m quite scared because idk how my body will react tomorrow. Are there any precautions I should take to prevent anything from occurring during the school day ?