a group of chicks i know deleted me on fb? is there a reason?

I'm sorry this might sound dumb, and im not in high school i keep my fb to keep in touch with friends and family. I was on fb the other day and i noticed four ladies i know that also know each other, literally all deleted me. I'm not sure when it was since i don't talk to them every day but every once in a while i'll make convo. So I msg'd one and asked if i had offended them in any way and she read the message and never replied. I'm completely stumped and honestly as i get older i've become a bit jaded almost like f it when things happen. It does bother me to think someone hates me and i'm oblivous why. Any idea what this could be about? also i mean I can't cry over spilled milk so not much i can do i suppose.