Teaching amidst COVID

Hey all! I guess I wanted some insight into my situation while 24 weeks pregnant and dealing with COVID in my classroom. We’ve had 3 positive cases in my classroom alone since the beginning of school 3 weeks ago. I teach 6th Grade Core. I’ve been under a great deal of stress as this variant has caused COVID to spike, and although I’m vaccinated, I can’t help but read how that doesn’t necessarily mean I’m protected, especially while in this vulnerable pregnant population. I’m considering telling my principal this is too much and starting leave super early just to keep baby protected from both COVID and mamas stress. I’d appreciate any thoughts or perspective, perhaps from moms in similar shoes even?