Plan B effectiveness?

so i’m confused. different people telling me different things and i also get different answers online. people tell me plan b will work at any time and then other people go and tell me it only works if you haven’t ovulated. i took it about a week before my expected period and people are telling me it won’t work. i have no idea when or if i ovulated this month but the app i use says i did on the 16th. idk if it’s true tho because this month is my first period in almost 2 years because i had an iud for like forever. im supposed to get my period on or around the first of november and i took the plan b on the 24th but i know the plan b can delay it. i’ve never taken a plan b so im just confused. Has anyone else taken a plan b around a week before their “expected” period date and it worked? because i’m freaking out over here lmao.

i’m not on birth control right now as im in the middle of switching my insurances so i can’t get an appt until November. thanks.