PLAN B -please help

Hi everyone, so I’m stressing out because I took a plan b and I was reading a lot about it failing for some, and how there’s a weight limit or it’s ineffective if you’re fertile or ovulating.

My period ended on Sat Nov 23rd and I had unprotected sex with my boyfriend on Wed 27th at about 1AM, I then took a plan B the same day at 8PM.

I was looking at my calendar and it said i was a day away from my fertile window. I don’t even know what the means tbh. Does that mean I can easily get pregnant?

Anyways, I was reading that if you’re already fertile it’s ineffective. Also, that it’s supposed to delay or stop you from ovulating that month. But I’m ovulating right now. So ?? I know the only way to ultimately know if I’m pregnant is to take a test, but It’s too soon to take a test and I’m stressing out so much. I can’t sleep.